Biochem J, 1992 Apr 1, 283 ( Pt 1), 87 - 90 Isolation and characterization of the cytochrome domain of flavocytochrome b2 expressed independently in Escherichia coli; Brunt CE et al.; The cytochrome domain of flavocytochrome b2 (L-lactate dehydrogenase) was expressed in the bacterium Escherichia coli and a purification procedure was developed . When expressed in E . coli, the b2-cytochrome domain contains protohaem IX and has an electronic absorption spectrum identical with that of the cytochrome b2 'core' produced by proteolytic cleavage of the enzyme isolated from yeast . The b2-cytochrome domain isolated from E . coli has an Mr of 10,500 and a redox potential of -31 +/- 2 mV . High-field n.m.r . studies indicate pKa values for the haem propionate groups to be 4.8 and 4.6, consistent with these groups being exposed to solvent rather than buried inside the protein . Using n.m.r . spectroscopy, we have determined an electron self-exchange rate constant for the b2-cytochrome domain of 2.3 x 10(6) M-1.s-1, which is more than two orders of magnitude larger than the value obtained for microsomal cytochrome b5, a homologue of b2-cytochrome domain. Infect Immun, 1992 Apr, 60(4), 1671 - 6 Identification of a second hemolysin (HlyII) in Actinobacillus pleuropneumoniae serotype 1 and expression of the gene in Escherichia coli; Frey J et al.; Hemolysin genes of the reference strains of Actinobacillus pleuropneumoniae serotypes 1 and 2 were identified, cloned, and expressed in Escherichia coli by using polymerase chain reaction amplification with oligonucleotides derived from the DNA sequence of the corresponding appA gene from A . pleuropneumoniae serotype 5 . The three genes from serotypes 1, 2, and 5 have identical restriction maps and appear to encode a hemolysin which was previously identified in serotype 2 and designated HlyII . Gene appA is different from hlyIA encoding the major hemolysin type I (HlyI) which was identified earlier in serotype 1 . Polymerase chain reaction amplification with oligonucleotides derived from the DNA sequence of hlyIA of serotype 1 showed that the gene encoding HlyI is present in serotype 1 but not in serotype 2, in contrast to the gene encoding HlyII that was present in both serotypes . This was confirmed by Western blot (immunoblot) experiments using monoclonal antibodies specific for either recombinant HlyI or recombinant HlyII, which showed that A . pleuropneumoniae serotype 1 strain 4074 produces both HlyI and HlyII, whereas serotype 2 strain S1536 produces only HlyII . The expression of both hemolysins was investigated in all serotypes by the use of monoclonal antibodies . HlyI was shown to be expressed by the reference strains of serotypes 1, 5a, 5b, 9, 10, and 11, whereas HlyII was shown to be expressed by the reference strains of all 12 serotypes tested except serotype 10 . A . pleuropneumoniae serotype 1 strain 4074 is the first bacterium which has been shown to contain two different actively expressed RTX toxin genes . Comparison of our data with those from other groups shows that the originally described strongly hemolytic hemolysin type I (HlyI) corresponds to cytolysin I (ClyI) which was recently described by others, while the weakly hemolytic hemolysin type II (HlyII) seems to be identical to ClyII and AppA. Infect Immun, 1992 Apr, 60(4), 1385 - 9 Lipopolysaccharide (LPS) from Brucella abortus is less toxic than that from Escherichia coli, suggesting the possible use of B . abortus or LPS from B . abortus as a carrier in vaccines; Goldstein J et al.; Brucella abortus may be useful as a component of vaccines . This is because it possesses several unique properties as a carrier that enable it to stimulate human B cells even in the relative absence of T cells . Human immunodeficiency virus type 1 proteins conjugated to B . abortus could induce neutralizing antibodies against human immunodeficiency virus type 1 . Recently we showed that the characteristics of lipopolysaccharide (LPS) derived from B . abortus are similar to those of the whole bacterium in that the LPS acts as a T-independent type 1 carrier in mice . In this study we wanted to determine whether LPS derived from B . abortus is associated with the adverse effects seen with other bacterial endotoxins . LPS purified from B . abortus by butanol extraction was shown to have less than 2% (wt/wt) contamination by protein and less than 1% (wt/wt) contamination by nucleic acids and to contain 1% (wt/wt) ketodeoxyoctanic acid . Compared with LPS derived from Escherichia coli, B . abortus LPS was 10,000-fold less potent in eliciting fever in rabbits, 268-fold less potent in killing D-galactosamine-sensitized mice, and 1,400-fold and 400-fold less potent in inducing interleukin-1 beta and tumor necrosis factor alpha production, respectively . These results suggest that B . abortus LPS is much less likely than the LPS from E . coli to evoke endotoxic shock; therefore, it may be feasible to incorporate B . abortus as a component of vaccines. J Appl Bacteriol, 1992 Apr, 72(4), 294 - 301 Use of the polymerase chain reaction and oligonucleotide probes for the rapid detection and identification of Carnobacterium species from meat; Brooks JL et al.; The polymerase chain reaction (PCR) was used selectively to amplify specific rDNA sequences of Carnobacterium divergens, C . mobile, C . piscicola and C . gallinarum in purified DNA extracts, crude cell lysates and food samples . The PCR products were visualized by agarose gel electrophoresis and identified, at species level, by hybridization reactions with three specific oligonucleotide probes for C . divergens, C . mobile and C . piscicola/C . gallinarum designed from 16S rRNA sequence data . The PCR was sufficiently sensitive to amplify DNA from a single bacterium to detectable levels after 30 cycles of amplification . Both radioactive (32P) and non-radioactive alkaline phosphatase labelled probes was able to detect the PCR products . Detection was highly specific and the probes did not hybridize with DNA samples from any other of the bacterial species tested . These methods enabled the rapid and specific detection and identification of carnobacteria from pure cultures and samples of meat. Surg Clin North Am, 1992 Apr, 72(2), 285 - 316 Medical therapy of peptic ulcer disease; McQuaid KR et al.; The gastric duodenal mucosa normally is protected from the damaging effects of gastric acid and pepsin by ill-defined mechanisms . Ulcers may arise when there is an imbalance between the aggressive and defensive factors that renders the mucosa susceptible to damage . A variety of factors have been identified that may favor the development of peptic ulcers, but no single pathophysiologic defect applies in all ulcer patients . In duodenal ulcers, gastric acid hypersecretion is observed in as many as one third of patients; however, most patients with duodenal ulcers secrete normal amounts of gastric acid . Decreased mucosal bicarbonate secretion may be important in at least some duodenal ulcer patients . Use of NSAIDs may cause either gastric or duodenal ulcers, probably through the inhibition of mucosal prostaglandin synthesis and disruption of mucosal defenses . Finally, a recently identified bacterium, H . pylori, causes a chronic gastritis that is found in the overwhelming majority of patients with duodenal ulcers and non-NSAID-associated gastric ulcers . This bacterium may play a pivotal role in ulcer pathogenesis and, especially, in ulcer recurrences . A number of drugs of proved efficacy are available for the treatment of acute duodenal and gastric ulcers . The H2 receptor antagonists administered once daily remain the mainstay of ulcer therapy because of their efficacy, ease of use, and excellent safety profile . More thorough and long-lasting acid inhibition is afforded by the H+/K(+)-ATPase inhibitor omeprazole . This agent also promotes more rapid ulcer healing, but in most patients, this minor advantage may not justify the higher cost . It is not known whether more rapid healing will translate into lower ulcer complication rates . Until further data are available, this drug may be preferable in patients with large or complicated ulcers . In patients with refractory ulcers, omeprazole is clearly superior to other available agents . Agents that promote mucosal defense mechanisms are becoming increasingly popular in the treatment of duodenal ulcers but have undergone less testing than in gastric ulcers . Sucralfate 1 g four times daily is equivalent to H2 antagonists in the treatment of duodenal ulcers and, probably, gastric ulcers . Its requirement for multiple daily doses makes it somewhat less attractive at present to most patients . Low- to medium-dose Al-containing antacids are inexpensive and efficacious in duodenal ulcer therapy . They should remain as therapeutic options for the compliant patient in whom cost considerations are important . Colloidal bismuth subcitrate 120 mg four times a day is comparable to other agents in the acute treatment of duodenal ulcers and likely gastric ulcers.(ABSTRACT TRUNCATED AT 400 WORDS) Biochemistry, 1992 Mar 31, 31(12), 3281 - 8 Biochemical and spectroscopic characterization of the high molecular weight cytochrome c from Desulfovibrio vulgaris Hildenborough expressed in Desulfovibrio desulfuricans G200; Bruschi M et al.; The gene of high molecular weight, multiheme cytochrome c (Hmc) from the sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough has been overexpressed in Desulfovibrio desulfuricans G200 . The recombinant protein has been purified . Its molecular weight (65,600), amino acid composition, and NH2-terminal sequence were found to be identical to those of the wild-type protein . The recombinant protein has been spectroscopically characterized (optical spectrum, EPR, circular dichroism) and compared to the wild-type protein . We have found 16 hemes per molecule by iron analysis and the pyridine hemochrome test . Both high- and low-spin features were observed in the EPR spectrum . A detailed spin quantitation analysis indicates 1 or 2 high-spin hemes and 14 or 15 low-spin hemes per molecule . The redox potentials of the hemes determined by voltammetric techniques gave an average of three different values, 0, -100, and -250 mV (versus NHE), for the wild-type and the recombinant cytochrome . The low potential values are similar to the values observed for the bis(histidinyl) coordinated hemes of cytochrome c3 . A comparison of the arrangement of heme binding sites and coordinated histidines in the amino acid sequences of cytochrome c3 and Hmc has shown that the latter contains four domains, three of which are complete c3-like domains, while the fourth represents an incomplete c3-like domain which may contain His-Met coordinated hemes . These data are in agreement with the detailed study of the number and types of hemes reported in this paper. J Biol Chem, 1992 Mar 15, 267(8), 5217 - 21 Purification, characterization, and nucleotide sequence of the thermolabile alpha-amylase from the antarctic psychrotroph Alteromonas haloplanctis A23; Feller G et al.; The alpha-amylase excreted by the antarctic bacterium Alteromonas haloplanctis was purified and the corresponding amy gene was cloned and sequenced . N- and C-terminal amino acid sequencing were used to establish the primary structure of the mature A . haloplanctis alpha-amylase which is composed of 453 amino acids with a predicted Mr of 49,340 and a pI of 5.5 . Three Ca2+ ions are bound per molecule and its activity is modulated by chloride ions . Within the four consensus sequences, Asp-174, Glu-200, and Asp-264 are the proposed catalytic residues . The psychrotrophic A . haloplanctis alpha-amylase is characterized by a high amylolytic activity at low temperatures, a reduced apparent optimal temperature, and typical thermodynamic activation parameters A . haloplanctis alpha-amylase has also a low thermal stability as demonstrated by the temperature effect on both activity and secondary structure . It is suggested that structure flexibility and lower sensitivity of secondary structure to temperature variations in the low temperature range are the main structural adaptations of the psychrotrophic enzyme . The unusual stacking of small amino acids around the catalytic residues is proposed as a factor inducing active site flexibility and concomitant high activity of the enzyme at low temperatures. Biochemistry, 1992 Mar 10, 31(9), 2608 - 14 Characterization of an improved reaction center preparation from the photosynthetic green sulfur bacterium Chlorobium containing the FeS centers FA and FB and a bound cytochrome subunit; Feiler U et al.; A photosynthetic reaction center complex was prepared from the green sulfur bacterium Chlorobium by solubilization of chlorosome-depleted membranes with lauryl maltoside, followed by anion-exchange chromatography and molecular sieve chromatography . The purified complex was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, optical spectroscopy, and EPR spectroscopy . The major bands migrated at apparent molecular masses of 50, 42, and 32 kDa (heme-staining) and additional weaker bands at 22, 15, and 12 kDa . The isolated reaction center complex contained about 40 bacteriochlorophyll alpha molecules per primary electron donor, P840, assayed by photooxidation . It was competent in stable low-temperature photoreduction of the FeS centers FA and FB . The spectra of these acceptors and their low-temperature photochemistry in the purified complex were the same as found in intact Chlorobium membranes and similar to what had been described for photosystem I from plants . Membrane-bound cytochrome c553 copurified with the reaction center complex . A ratio of about four hemes per P840 was determined . This result indicates that cytochrome c553 that is closely associated with the reaction center is a tetraheme cytochrome, as described for some purple bacteria. FEBS Lett, 1992 Mar 9, 299(2), 127 - 30 Sulfide quinone reductase (SQR) activity in Chlorobium; Shahak Y et al.; Membranes of the green sulfur bacterium, Chlorobium limicola f . thiosulfatophilum, catalyze the reduction of externally added isoprenoid quinones by sulfide . This activity is highly sensitive to stigmatellin and aurachins . It is also inhibited by 2-n-nonyl-4-hydroxyquinoline-N-oxide, antimycin, myxothiazol and cyanide . It is concluded that in sulfide oxidizing bacteria like Chlorobium, sulfide oxidation involves a sulfide-quinone reductase (SQR) similar to the one found in Oscilatoria limnetica {Arieli, B., Padan, E . and Shahak, Y . (1991) J . Biol . Chem . 266, 104-111}. Biochemistry, 1992 Mar 3, 31(8), 2316 - 28 Structural similarity of D-aminopeptidase to carboxypeptidase DD and beta-lactamases; Asano Y et al.; The gene for D-aminopeptidase (dap) has been isolated from the bacterium Ochrobactrum anthropi SCRC C1-38 {Asano, Y., Nakazawa, A., Kato, Y., & Kondo, K . (1989) J . Biol . Chem . 264, 14233-14239} and its nucleotide sequence determined . An expression plasmid pC138DP (4.5 kb) was constructed by placing the gene downstream of the lac promoter of pUC19 . The amount of the enzyme in the cell-free extract of Escherichia coli JM109/pC138DP was elevated to 288,000 units/L of culture, which is about 3600-fold over that of O . anthropi SCRC C1-38 . The enzyme comprised about 30% of the total extractable cellular protein . The gene consisted of an open reading frame of 1560 nucleotides which specifies a protein of Mr 57,257 . The deduced amino acid sequence of the enzyme showed that it is related to carboxypeptidase DD, beta-lactamases, and penicillin-binding proteins . Seven mutants of the enzyme were generated by site-specific mutagenesis to explore the roles of the residues of interest, around the sequence Ser61-Xaa-Xaa-Lys64, where Xaa is any amino acid, since the identical sequences also appear in the penicillin-recognizing peptide hydrolases with Ser at the active sites . The mutant enzymes expressed in E . coli were purified to homogeneity and kinetically characterized . Replacements of the site at Ser61 and Lys64 yielded mutants showing significantly reduced Vmax values, while most of the Km values remained unchanged . Changes at Cys60, which is adjacent to the likely active center Ser61, to Ser and Gly resulted in the production of enzyme less sensitive to PCMB, with almost unaltered Vmax/Km values . The enzyme appears to be a serine peptidase rather than a thiol one . The inhibition by PCMB in the wild-type enzyme may have been caused by a formation of a mercaptide bond between Cys 60 and PCMB . Considering that D-aminopeptidase, carboxypeptidase DD (a penicillin-binding protein), and beta-lactamase have a common feature in recognizing peptides containing D-amino acid and that the former two catalyze transpeptidation reactions with substrates containing D-alanyl-D-alanine moieties, we propose that the enzyme is a new member of the "penicillin-recognizing enzymes" . We showed that the enzyme is actually inhibited by beta-lactam compounds, such as 6-APA, 7-ACA, benzylpenicillin, and ampicillin, although they are not the substrate for the enzyme . The relationship between the primary structures and the reactions catalyzed by D-aminopeptidase and other serine hydrolases beta-lactamases and carboxypeptidase DD is discussed.(ABSTRACT TRUNCATED AT 400 WORDS) J Gen Microbiol, 1992 Mar, 138 ( Pt 3), 429 - 36 Linear growth and poly(beta-hydroxybutyrate) synthesis in response to pulse-wise addition of the growth-limiting substrate to steady-state heterotrophic continuous cultures of Aquaspirillum autotrophicum; Pagni M et al.; Heterotrophic pyruvate-limited steady-state continuous cultures of the bacterium Aquaspirillum autotrophicum were perturbed with a pulse injection of a small volume of concentrated pyruvate solution . These cultures exhibited an instantaneous change in the growth dynamics, turning from steady state to apparently linear growth . These transient growth-responses had no lag phase and were clearly distinct from unlimited exponential growth according to the initial rates of increase of biomass and substrate disappearance kinetics . A linear accumulation with time of poly(beta-hydroxybutyrate) was observed within the cells . Slopes of these linear responses were negatively correlated with the dilution rate . Physiological bases of linear growth are discussed in the light of the models of H . E . Kubitschek . Poly(beta-hydroxybutyrate) synthesis in the absence of exogenous limitation may serve to protect the cells against a transient metabolic overflow. Mol Gen Genet, 1992 Mar, 232(1), 74 - 80 Spontaneous and reversible high-frequency frameshifts originating a phase transition in the carotenoid biosynthesis pathway of the phototrophic bacterium Rhodobacter sphaeroides 2.4.1; Gari E et al.; The synthesis of carotenoids in strain 2.4.1 of the phototrophic bacterium Rhodobacter sphaeroides is spontaneously turned on and off at a high frequency (10(-5) per cell per generation) giving rise alternatively to red (wild type) and green (mutant) clones . The crtD gene is not functional in green mutants as a consequence of the spontaneous addition of a guanosine in a stretch of seven guanosines located in the 5'-terminal coding region of this gene originating a frameshift . All spontaneous wild-type revertants isolated from green mutants had recovered the crtD gene function by loss of one of these reiterated guanosines . The transition Crt(+)----Crt(-)----Crt+, is strain-dependent, since Crt+ clones were not detected in ethyl methane sulphonate (EMS)-induced CrtD- mutants of two other strains of R . sphaeroides (WS22 and RS630) which harbour a recombinant plasmid containing the crtD gene from a spontaneous CrtD- mutant of strain 2.4.1 of R . sphaeroides. J Bacteriol, 1992 Mar, 174(6), 1726 - 33 Nucleotide sequence of dcrA, a Desulfovibrio vulgaris Hildenborough chemoreceptor gene, and its expression in Escherichia coli; Dolla A et al.; The amino acid sequence of DcrA (Mr = 73,000), deduced from the nucleotide sequence of the dcrA gene from the anaerobic, sulfate-reducing bacterium Desulfovibrio vulgaris Hildenborough, indicates a structure similar to the methyl-accepting chemotaxis proteins from Escherichia coli, including a periplasmic NH2-terminal domain (Mr = 20,700) separated from the cytoplasmic COOH-terminal domain (Mr = 50,300) by a hydrophobic, membrane-spanning sequence of 20 amino acid residues . The sequence homology of DcrA and these methyl-accepting chemotaxis proteins is limited to the COOH-terminal domain . Analysis of dcrA-lacZ fusions in E . coli by Western blotting (immunoblotting) and activity measurements indicated a low-level synthesis of a membrane-bound fusion protein of the expected size (Mr = approximately 137,000) . Expression of the dcrA gene under the control of the Desulfovibrio cytochrome c3 gene promoter and ribosome binding site allowed the identification of both full-length DcrA and its NH2-terminal domain in E . coli maxicells. Infect Immun, 1992 Mar, 60(3), 937 - 43 Deformation factor: an extracellular protein synthesized by Bartonella bacilliformis that deforms erythrocyte membranes; Mernaugh G et al.; Bartonella bacilliformis, a hemotropic bacterium and the causative agent of the human disease bartonellosis, when incubated in a tryptone-based medium produces an extracellular factor, termed deformation factor (DF), which induces extensive indentations and trenches in trypsinized erythrocyte membranes . The factor is stable during storage at 4 degrees C . It can be inactivated by proteases or brief heating to 70 to 80 degrees C, can be precipitated by ammonium sulfate, is nondialyzable, and is retained by membranes with a 30,000-molecular-weight cutoff . These properties suggest that DF is probably a protein . Incubation of erythrocytes with phospholipase D renders them resistant to deformation by DF. Infect Immun, 1992 Mar, 60(3), 817 - 25 Activation of macrophages for destruction of Francisella tularensis: identification of cytokines, effector cells, and effector molecules; Fortier AH et al.; Francisella tularensis live vaccine strain (LVS) was grown in culture with nonadherent resident, starch-elicited, or Proteose Peptone-elicited peritoneal cells . Numbers of bacteria increased 4 logs over the input inoculum in 48 to 72 h . Growth rates were faster in inflammatory cells than in resident cells: generation times for the bacterium were 3 h in inflammatory cells and 6 h in resident macrophages . LVS-infected macrophage cultures treated with lymphokines did not support growth of the bacterium, although lymphokines alone had no inhibitory effects on replication of LVS in culture medium devoid of cells . Removal of gamma interferon (IFN-gamma) by immunoaffinity precipitation rendered lymphokines ineffective for induction of macrophage anti-LVS activity, and recombinant IFN-gamma stimulated both resident and inflammatory macrophage populations to inhibit LVS growth in vitro . Inflammatory macrophages were more sensitive to effects of IFN-gamma: half-maximal activity was achieved at 5 U/ml for inflammatory macrophages and 20 U/ml for resident macrophages . IFN-gamma-induced anti-LVS activity correlated with the production of nitrite (NO2-), an oxidative end product of L-arginine-derived nitric oxide (NO) . Anti-LVS activity and nitrite production were both completely inhibited by the addition of either the L-arginine analog NG-monomethyl-L-arginine or anti-tumor necrosis factor antibodies to activated macrophage cultures . Thus, macrophages can be activated by IFN-gamma to suppress the growth of F . tularensis by generation of toxic levels of NO, and inflammatory macrophages are substantially more sensitive to activation activities of IFN-gamma for this effector reaction than are more differentiated resident cells. Eur J Biochem, 1992 Mar 1, 204(2), 531 - 7 Arginine catabolism in the phototrophic bacterium Rhodobacter capsulatus E1F1 . Purification and properties of arginase; Moreno-Vivian C et al.; The phototrophic bacterium Rhodobacter capsulatus E1F1 grew with L-arginine or L-homoarginine as nitrogen source under light/anaerobiosis . However, when L-arginine was used as the only source of both carbon and nitrogen, the bacterium exhibited weak growth levels and the excess of nitrogen was excreted to the medium as ammonia . By contrast, L-ornithine was used under phototrophic conditions as either nitrogen or carbon source . Other compounds of the arginine catabolic pathways, such as putrescine or proline, also supported phototrophic growth of this bacterium . Under heterotrophic/dark conditions, R . capsulatus always showed a low growth rate with those nitrogen compounds . Cells growing on media containing L-arginine, L-homoarginine or L-ornithine induced an Mn(2+)-dependent arginase activity regardless of the presence of ammonium ions and other readily utilizable nitrogen sources . Arginase activity was strongly inhibited by Zn2+, Cu2+, borate, L-cysteine, L-ornithine and gamma-guanidinobutyrate . Mercurials also inactivated arginase, the activity being partially restored by the presence of thiols . Arginase was purified to electrophoretic homogeneity and found to consist of four identical subunits of 31 kDa . The molecular parameters and kinetic constants of arginase from R . capsulatus E1F1 resembled those previously described for the Saccharomyces cerevisiae enzyme rather than those of bacterial arginases. J Infect Dis, 1992 Mar, 165(3), 484 - 93 Virulent Treponema pallidum activates human vascular endothelial cells; Riley BS et al.; Perivascular lymphocytic infiltration, fibrin deposition, and endothelial cell abnormalities consistent with cellular activation are prominent histopathologic features of syphilis, a sexually transmitted disease caused by the spirochetal bacterium Treponema pallidum . Because activated endothelial cells play important roles in lymphocyte homing and hemostasis, the ability of virulent T . pallidum to activate cultured human umbilical vein endothelial cells (HUVEC) was investigated . T . pallidum induced the expression of intercellular adhesion molecule-1 (ICAM-1) and procoagulant activity on the surface of HUVEC . Electron microscopy of T . pallidum-stimulated HUVEC revealed extensive networks of fibrin strands not observed in cultures without treponemes . ICAM-1 expression in HUVEC also was promoted by a 47-kDa integral membrane lipoprotein purified from T . pallidum, implicating a role for spirochete membrane lipoproteins in endothelial cell activation . The combined findings are consistent with the pathology of syphilis and provide the first evidence that a pathogenic spirochetal bacterium such as T . pallidum or its constituent integral membrane lipoprotein(s) can activate directly host vascular endothelium. FEMS Microbiol Lett, 1992 Mar 1, 70(2), 113 - 7 TRC-1: emergence of a clavulanic acid-resistant TEM beta-lactamase in a clinical strain; Thomson CJ et al.; A novel TEM-derived plasmid-encoded beta-lactamase, resistant to inhibition by clavulanic acid, has been identified in a clinical strain of Escherichia coli found in Scotland . The beta-lactamase gene was carried on an 81-kb plasmid that conferred no other resistances . The novel enzyme conferred resistance to the amoxycillin/clavulanic acid combination on the host bacterium . The beta-lactamase has a pI of 5.25 and lies between the PSE-4 and SAR-1 beta-lactamases on an isoelectric focusing gel . This beta-lactamase has a Mr value of 25,000, similar to the TEM-1 enzyme and a comparable substrate profile . Its most significant difference is that it is inhibited by clavulanic acid 100-fold less efficiently than the TEM-1 enzyme . The enzyme was confirmed to be derived from the TEM enzymes by probing the plasmid DNA with an intragenic gene probe for TEM-1 . This is the first report of a clinical bacterium carrying a TEM-enzyme that confers resistance to clavulanic acid combinations and we have designated the beta-lactamase as TRC-1. Appl Environ Microbiol, 1992 Mar, 58(3), 1070 - 2 Comparison of extracellular peroxidase- and esterase-deficient mutants of Streptomyces viridosporus T7A; Magnuson TS et al.; Peroxidase-deficient mutants of the lignin-degrading bacterium Streptomyces viridosporus T7A were screened for their production of acid-precipitable polymeric lignin, extracellular peroxidases and esterases, and immunoreactivities against a polyclonal antibody produced against electrophoretically purified peroxidase isoform P3 of wild-type S . viridosporus . The mutants showed diminished abilities to solubilize lignin and produce acid-precipitable polymeric lignin . Their peroxidase activities were decreased, and their esterase production patterns were altered . Western immunoblots demonstrated that the mutants produced proteins immunologically reactive with the antibody, but with different mobilities from those of wild-type proteins . These findings confirm a direct role for peroxidases in lignin solubilization . They also indicate a possible role for esterases. Nature, 1992 Feb 27, 355(6363), 848 - 50 Genetically modified photosynthetic antenna complexes with blueshifted absorbance bands; Fowler GJ et al.; Light energy for photosynthesis is collected by the antenna system, creating an excited state which migrates energetically 'downhill' . To achieve efficient migration of energy the antenna is populated with a series of pigments absorbing at progressively redshifted wavelengths . This variety in absorbing species in vivo has been created in a biosynthetically economical fashion by modulating the absorbance behaviour of one kind of (bacterio)chlorophyll molecule . This modulation is poorly understood but has been ascribed to pigment-pigment and pigment-protein interactions . We have examined the relationship between aromatic residues in antenna polypeptides and pigment absorption, by studying the effects of site-directed mutagenesis on a bacterial antenna complex . A clear correlation was observed between the absorbance of bacteriochlorophyll a and the presence of two tyrosine residues, alpha Tyr44 and alpha Tyr45, in the alpha subunit of the peripheral light-harvesting complex of Rhodobacter sphaeroides, a purple photosynthetic bacterium that provides a well characterized system for site-specific mutagenesis . By constructing single (alpha Tyr44, alpha Tyr45----PheTyr) and then double (alpha Tyr44, alpha Tyr45----PheLeu) site-specific mutants, the absorbance of bacteriochlorophyll was blueshifted by 11 and 24 nm at 77 K, respectively . The results suggest that there is a close approach of tyrosine residues to bacteriochlorophyll, and that this proximity may promote redshifts in vivo. Biochemistry, 1992 Feb 25, 31(7), 2093 - 8 Photocycle of phoborhodopsin from haloalkaliphilic bacterium (Natronobacterium pharaonis) studied by low-temperature spectrophotometry; Hirayama J et al.; Phoborhodopsin (pR) is the fourth retinal pigment of Halobacterium halobium and works as a photoreceptor for the negative phototactic response . A similar pigment was previously found in haloalkaliphilic bacterium (Natronbacterium pharaonis) and also works as the receptor of the negative phototactic response; this pigment is called pharaonis phoborhodopsin (ppR) . In this paper, the photocycle of ppR was investigated by means of low-temperature spectrophotometry . The absorption maximum of ppR is located at 498 nm, while that of pR is at 487 nm . The absorption spectra of the two have similar vibrational structures . Irradiation of ppR below -100 degrees C produced a K-like intermediate (ppRK) which was a composite of two components . The original ppR and ppRK were perfectly photoreversible . On warming, ppRK was directly converted to an M-like intermediate without formation of the L-like intermediate . The M-like intermediate was converted to the O-like intermediate at pH 7.2, but the O-like intermediate was not detected at pH 9.0 . The O-like intermediate then reverted to the original pigment . On the basis of these findings, the photocycle and the primary photochemical process of ppR are presented. Orv Hetil, 1992 Feb 9, 133(6), 359 - 61 {Helicobacter pylori allergy}; Varga L et al.; A case of a 44 year old woman with antrum gastritis and H . pylori infection was reported . After unsuccessful treatment of the disorder with bismuth and tinidazole, an auto-vaccine was prepared from the bacterium in order to eliminate the infection . After the first injection of the vaccine a generalised urticaria was observed . In the development of the skin eruptions a type I, and a type IV allergic reaction could be demonstrated using the H . pylori specific RAST-test and leukocyte migration inhibition respectively . After eradication of the bacterium by amoxycillin treatment, the clinical signs of both the gastrointestinal and allergic diseases disappeared. J Exp Med, 1992 Feb 1, 175(2), 517 - 25 Surface proteins from Helicobacter pylori exhibit chemotactic activity for human leukocytes and are present in gastric mucosa; Mai UE et al.; The mechanism by which Helicobacter pylori, a noninvasive bacterium, initiates chronic antral gastritis in humans is unknown . We now show that H . pylori releases products with chemotactic activity for monocytes and neutrophils . This chemotactic activity was inhibited by antisera to either H . pylori whole bacteria or H . pylori-derived urease . Moreover, surface proteins extracted from H . pylori and purified H . pylori urease (a major component of the surface proteins) exhibited dose-dependent, antibody-inhibitable chemotactic activity . In addition, a synthetic 20-amino acid peptide from the NH2-terminal portion of the 61-kD subunit, but not the 30-kD subunit, of urease exhibited chemotactic activity for monocytes and neutrophils, localizing the chemotactic activity, at least in part, to the NH2 terminus of the 61-kD subunit of urease . The ability of leukocytes to chemotax to H . pylori surface proteins despite formyl-methionyl-leucyl-phenylalanine (FMLP) receptor saturation, selective inhibition of FMLP-mediated chemotaxis, or preincubation of the surface proteins with antiserum to FMLP indicated that the chemotaxis was not FMLP mediated . Finally, we identified H . pylori surface proteins and urease in the lamina propria of gastric antra from patients with H . pylori-associated gastritis but not from uninfected subjects . These findings suggest that H . pylori gastritis is initiated by mucosal absorption of urease, which expresses chemotactic activity for leukocytes by a mechanism not involving N-formylated oligopeptides. Acta Crystallogr B, 1992 Feb 1, 48 ( Pt 1), 42 - 59 Refinement of rubredoxin from Desulfovibrio vulgaris at 1.0 A with and without restraints; Dauter Z et al.; X-ray data have been recorded from crystals of rubredoxin derived from the bacterium Desulfovibrio vulgaris to a resolution of 1.0 A using in part synchrotron radiation and in part X-rays from a sealed-tube Mo K alpha source . In both cases an imaging-plate scanner was used as detector . The space group of the crystals is P2(1) with cell dimensions a = 19.97, b = 41.45, c = 24.41 A and beta = 108.3 degrees . The overall merging R(I) factor between symmetry-related reflections was 5.8% . The model was refined by least-squares minimization initially with stereochemical restraints to an R factor of 16.4% . Only atomic positional parameters and isotropic temperature factors for non-H atoms were used in the refinement . There were 18,532 independent X-ray observations for a total of 1916 atomic parameters . A round of unrestrained refinement gave an R factor of 16.0%, acceptable geometry for more than 90% of the protein atoms, but emphasized the disorder inherent in eight of the residues . A final round of restrained refinement gave an R factor of 14.7% . Three of the 389 protein atoms in the molecule, in the side chain of Lys2, have been assigned zero occupancy in the model . A total of eight atoms in three side chains have been assigned two conformations, giving 393 protein atomic sites in the model . In addition there is one Fe atom, a sulfate ion and 102 water sites . 339 H atoms were included at their calculated positions, which were not refined . There is clear evidence for anisotropic thermal motion . This has not been incorporated in the present model. Appl Environ Microbiol, 1992 Feb, 58(2), 690 - 5 Light-dependent degradation of nitrophenols by the phototrophic bacterium Rhodobacter capsulatus E1F1; Blasco R et al.; Rhodobacter capsulatus E1F1, a phototrophic purple nonsulfur bacterium capable of photoassimilating nitrate or nitrite, grew phototrophically in the presence of mono- and dinitrophenols with acetate as a carbon source, the highest growth levels being obtained under microaerobic conditions . Utilization of 2,4-dinitrophenol was strictly light dependent, was inhibited by O2 and by ammonium, and took place with the simultaneous and stoichiometric production of 2-amino-4-nitrophenol, which accumulated in the medium and was poorly used for further growth in anaerobiosis . Metabolism of mononitrophenols was also light dependent but was activated by O2 and by ammonium . Metabolism of nitrophenols seemed to depend on inducible systems which were repressed in nitrogen-starved cells . Induction of the in vivo 2,4-dinitrophenol reducing system was strongly inhibited by chloramphenicol. Proteins, 1992 Feb, 12(2), 117 - 27 Electrostatic fields at the active site of ribulose-1,5-bisphosphate carboxylase; Lu GG et al.; A macroscopic approach has been employed to calculate the electrostatic potential field of nonactivated ribulose-1,5-bisphosphate carboxylase and of some complexes of the enzyme with activator and substrate . The overall electrostatic field of the L2-type enzyme from the photosynthetic bacterium Rhodospirillum rubrum shows that the core of the dimer, consisting of the two C-terminal domains, has a predominantly positive potential . These domains provide the binding sites for the negatively charged phosphate groups of the substrate . The two N-terminal domains have mainly negative potential . At the active site situated between the C-terminal domain of one subunit and the N-terminal domain of the second subunit, a large potential gradient at the substrate binding site is found . This might be important for polarization of chemical bonds of the substrate and the movement of protons during catalysis . The immediate surroundings of the activator lysine, K191, provide a positive potential area which might cause the pK value for this residue to be lowered . This observation suggests that the electrostatic field at the active site is responsible for the specific carbamylation of the epsilon-amino group of this lysine side chain during activation . Activation causes a shift in the electrostatic potential at the position of K166 to more positive values, which is reflected in the unusually low pK of K166 in the activated enzyme species . The overall shape of the electrostatic potential field in the L2 building block of the L8S8-type Rubisco from spinach is, despite only 30% amino acid homology for the L-chains, strikingly similar to that of the L2-type Rubisco from Rhodospirillum rubrum . A significant difference between the two species is that the potential is in general more positive in the higher plant Rubisco . In particular, the second phosphate binding site has a considerably more positive potential, which might be responsible for the higher affinity for the substrate of L8S8-type enzymes . The higher potential at this site might be due to two remote histidine residues, which are conserved in the plant enzymes. J Antibiot (Tokyo), 1992 Feb, 45(2), 269 - 77 Characterization of an inducible transport system for glycerol in Streptomyces clavuligerus . Repression by L-serine; Minambres B et al.; Streptomyces clavuligerus NRRL 3585 grown in a chemically defined medium containing glycerol as the sole carbon source transported this molecule by two different systems . One of these was constitutive with a very low uptake efficiency and insufficient to attend to the metabolic requirements of this bacterium (constitutive glycerol transport system) and the other (glycerol transport system (GTS)) active and specifically induced by D-glycerol which is responsible for the transport of more than 90% of the glycerol taken up the cells . GTS was seen to have an optimal pH and temperature of 7.0 and 30 degrees C, respectively, and its Km was 14 microM . It was repressed by L-serine and addition of this amino acid to the culture broth (10 mM) inhibited the growth of S . clavuligerus but not that of other species of Streptomyces. EMBO J, 1992 Feb, 11(2), 777 - 83 A system for site-specific mutagenesis of the photosynthetic reaction center in Rhodopseudomonas viridis; Laussermair E et al.; The purple non-sulfur bacterium Rhodopseudomonas viridis contains a photosynthetic reaction center which has been structurally resolved to 2.3 A providing a unique basis for the study of biological electron transfer processes by the method of site-specific mutagenesis . Here we report the construction of a puf operon deleted mutant strain incapable of photosynthetic growth . The deletion was introduced with the help of a newly constructed suicide vector by electroporation which is with conjugation another gene transfer system for R . viridis . The deletion strain was complemented by conjugational gene transfer with wild-type (WT) and mutated LM genes of the puf operon . The complemented WT and mutations YL162F and HL153F grew photosynthetically, expressed and assembled the four subunits L, M, H and Cyt c of the reaction center correctly . These first mutations already demonstrate the value of the R . viridis system for a detailed structure-function analysis of photosynthetic electron transfer. J Membr Biol, 1992 Feb, 125(3), 255 - 71 Ion selectivity of colicin E1: modulation by pH and membrane composition; Bullock JO; Colicin E1 is a plasmid-encoded bacteriocidal protein which, though water soluble when secreted by its host bacterium, spontaneously interacts with planar lipid bilayers to form voltage-gated ion channels . In asolectin bilayers, the preference for anions over cations exhibited by these channels at low pH can be reversed by raising the pH on either side of the membrane . When incorporated into membranes composed of either of the two zwitterionic lipids, bacterial phosphatidylethanolamine and diphytanoyl phosphatidylcholine, colicin E1 channels were nearly ideally anion selective in the limit of low pH and moderately cation selective at the high pH limit . In phosphatidylcholine membranes, however, the response of these channels to changes in pH exhibited a pattern of behavior peculiar to this lipid . If the side of the membrane on which the protein had been introduced (the cis side) was exposed to pH 4.0, all the channels in the bilayer, whether opened or closed, became refractory to further changes in pH . This irreversibility has been interpreted as evidence that the selectivity of colicin E1 is under the control of a pH-sensitive conformational change . Protonation of groups on the cis side of the membrane appear to be essential to the conversion to the anion-selective state . These groups are rendered kinetically inaccessible to the aqueous phase when the transition takes place in phosphatidylcholine membranes. FEBS Lett, 1992 Jan 20, 296(2), 169 - 73 The major Thiobacillus ferrooxidans outer membrane protein forms low conductance ion channels in planar lipid bilayers; Silva M et al.; A protein isolated and purified from the outer membrane of the acidophilic, chemolithotrophic bacterium, Thiobacillus ferrooxidans with an oligomeric molecular weight of 90,000 Da (p90) was incorporated into phosphatidylethanolamine planar lipid bilayers . The protein formed slightly anionic channels in KCl solutions, with a conductance of 25 pS in 100 mM KCl . The current-voltage relationship was linear between +/- 60 mV, and the conductance was a saturating function of the salt concentration . These channels fluctuated from a single open to closed state at low potentials, but present flickering activity at higher potentials. Int J Syst Bacteriol, 1992 Jan, 42(1), 27 - 36 Helicobacter muridarum sp . nov., a microaerophilic helical bacterium with a novel ultrastructure isolated from the intestinal mucosa of rodents; Lee A et al.; Helical organisms with novel ultrastructural characteristics were isolated from the intestinal mucosa of rats and mice . These bacteria were characterized by the presence of 9 to 11 periplasmic fibers which appeared as concentric helical ridges on the surface of each cell . The cells were motile with a rapid corkscrewlike motion and had bipolar tufts of 10 to 14 sheathed flagella . The bacteria were microaerophilic, nutritionally fastidious, and physiologically similar to Helicobacter species and Wolinella succinogenes but could be differentiated from these organisms by their unique cellular ultrastructure . Using 16S rRNA sequencing, we found that strain ST1T (T = type strain) was related to previously described Helicobacter species, "Flexispira rappini," and W . succinogenes . The closest relatives of strain ST1T were Helicobacter mustelae and "F . rappini" (average similarity value, 96%) . On the basis of phylogenetic data, strain ST1T (= ATCC 49282T) represents a new species of the genus Helicobacter, for which we propose the name Helicobacter muridarum. Mol Gen Genet, 1992 Jan, 231(2), 323 - 8 Transcriptional analysis and promoter mapping of the fdxA gene which encodes the 7Fe ferredoxin (FdII) of Rhodobacter capsulatus; Duport C et al.; The structural gene (fdxA) coding for ferredoxin II (FdII) of the photosynthetic bacterium Rhodobacter capsulatus has been previously cloned and sequenced . Transcription of the fdxA gene was studied by mRNA analyses and by use of plasmid-borne fdxA::lacZ translational fusions . The transcription start site was mapped 23 bp upstream of the initiation codon, as deduced from analysis of mRNA by mung bean nuclease protection and primer extension experiments . A motif resembling the canonical sequence observed in sigma 70-dependent Escherichia coli promoters is present at the expected distance (-10/-35) from the proposed transcription start site . mRNA analysis by Northern hybridization revealed a fdxA-specific transcript of approximately 0.4 kb, indicating that fdxA is transcribed as a single gene.fdxA expression, as measured by the activity of the fdxA::lacZ fusion, was found to be constant during growth and reached a similar level under all growth conditions tested . These results suggest that FdII is constitutively synthesized in R . capsulatus. Br J Rheumatol, 1992 Jan, 31(1), 67 - 9 Total knee arthroplasty infection due to Gemella haemolysans; Eggelmeijer F et al.; Gemella haemolysans, a relatively unknown commensal of the upper respiratory tract, rarely causes clinically important infections . This report deals with an infection of a total knee arthroplasty due to Gemella haemolysans in a patient with rheumatoid arthritis . The microbiology of this bacterium is discussed and the clinical features of previously reported cases of Gemella infections are briefly reviewed. J Immunol, 1992 Jan 1, 148(1), 189 - 96 T lymphocytes mediating protection and cellular cytolysis during the course of Mycobacterium tuberculosis infection . Evidence for different kinetics and recognition of a wide spectrum of protein antigens; Orme IM et al.; Recent evidence suggests the existence of at least two pathways of acquired specific resistance to Mycobacterium tuberculosis infection; the first consisting of cytokine-mediated activation of parasitized host cells by protective T cells, and the second involving the lysis of these cells by cytolytic T cells . Evidence presented in this report shows that both of the above mechanisms are operative in experimentally infected mice, but that they differ markedly in terms of their kinetics of emergence and loss . It was found that protective T cell activity was acquired very early during the course of the infection, and was temporally associated with the onset of bacterial elimination; however, cytolytic activity did not peak until 10 to 20 days later . This report shows further that the target Ag of these effector T cell populations were apparently numerous with no evidence for preferential recognition of a few immunodominant Ag . In view of the preponderance of target proteins in the bacterial filtrate, we present the hypothesis that such proteins secreted or otherwise leaked from the dividing mycobacterium are pinocytosed from the phagosome and used by the infected macrophage as the key protective Ag leading to T cell sensitization . This hypothesis thus explains the preferential requirement for the viable bacterium in the generation of specific resistance, and further explains why protective immunity is generated even while the organism is still multiplying in an apparently unrestrained manner. Scand J Infect Dis, 1992, 24(2), 161 - 4 Prevalence of Mycoplasma pneumoniae in subjectively healthy individuals; Gnarpe J et al.; Subjectively healthy persons were investigated for the presence of Mycoplasma pneumoniae in throat cultures . During a peak period of M . pneumoniae incidence, 13.5% of 758 healthy volunteers were found to harbour the bacterium in the throat . The investigation was continued, and during a subsequent period of 11 months, the incidence of M . pneumoniae isolated decreased to 4.6% of 499 volunteers . All new blood donor sera 1990-1991 (422 sera) were screened for the presence of antibodies to M . pneumoniae; it was found that there was a fluctuating but significant number of individuals with positive serology based on a single test occasion. Res Microbiol, 1992 Jan, 143(1), 75 - 9 Mycobacterium paratuberculosis binds fibronectin; Valentin-Weigand P et al.; Fibronectin, an adhesive glycoprotein which is present in plasma and on many host cell surfaces of many host organisms, binds to certain bacterial pathogens . This study demonstrates the ability of Mycobacterium paratuberculosis (M.ptb) to interact with 125I-labelled fibronectin purified from bovine and ovine plasma . Two M.ptb strains were tested: a clinical isolate and a commercially available vaccine strain . Both strains showed significant fibronectin-binding activities of 22 and 41%, respectively, whereas non-pathogenic M.phlei had almost no affinity for fibronectin . Binding activities were similar for ovine and bovine fibronectin . We found that fibronectin binding by M.ptb was (1) time-dependent, reaching saturation within 90 min, (2) specific, since it was inhibited by an excess of unlabelled fibronectin but not by albumin, (3) saturable, with an apparent dissociation constant of 1.25 x 10(-9) M and a maximal number of 1,600 binding sites per bacterium, and (4) sensitive to detergents, proteases and heat treatments, indicating the protein nature of the responsible binding component(s) . Scatchard plot analysis gave a straight line suggesting the presence of a single type of fibronectin receptor on M.ptb. Res Microbiol, 1992 Jan, 143(1), 47 - 54 N-unsubstituted glucosamine residues and other modifications in murein of the obligatory chemolithotroph Thiobacillus neapolitanus; Baj J et al.; Purified murein from Thiobacillus neapolitanus was poorly digested by lysozyme . It's sensitivity to the enzyme greatly increased after N-acetylation . The murein was found to contain 30 to 35% glucosamine residues lacking N-acetyl groups . It also contained phosphomuramic acid . Further modifications included amidation of diaminopimelic acid in the peptide side chains and a low alanine content . None of these modifications were found in the murein of another sulphur bacterium, Thiobacillus versutus. Arch Microbiol, 1992, 157(2), 148 - 54 Anaerobic degradation of trans-cinnamate and omega-phenylalkane carboxylic acids by the photosynthetic bacterium Rhodopseudomonas palustris: evidence for a beta-oxidation mechanism; Elder DJ et al.; The mechanism responsible for the initial steps in the anaerobic degradation of trans-cinnamate and omega-phenylalkane carboxylates by the purple non-sulphur photosynthetic bacterium Rhodopseudomonas palustris was investigated . Phenylacetate did not support growth and there was a marked CO2 dependence for growth on acids with greater side-chain lengths . Here, CO2 was presumably acting as a redox sink for the disposal of excess reducing equivalents . Growth on benzoate did not require the addition of exogenous CO2 . Aromatic acids with an odd number of side-chain carbon atoms (3-phenylpropionate, 5-phenylvalerate, 7-phenylheptanoate) gave greater apparent molar growth yields than those with an even number of side-chain carbon atoms (4-phenylbutyrate, 6-phenylhexanoate, 8-phenyloctanoate) . HPLC analysis revealed that phenylacetate accumulated and persisted in the culture medium during growth on these latter compounds . Cinnamate and benzoate transiently accumulated in the culture medium during growth on 3-phenylpropionate, and benzoate alone accumulated transiently during the course of trans-cinnamate degradation . The transient accumulation of 4-phenyl-2-butenoic acid occurred during growth on 4-phenylbutyrate, and phenylacetate accumulated to a 1:1 molar stoichiometry with the initial 4-phenylbutyrate concentration . It is proposed that the initial steps in the anaerobic degradation of trans-cinnamate and the group of acids from 3-phenylpropionate to 8-phenyloctanoate involves beta-oxidation of the side-chain. Appl Environ Microbiol, 1992 Jan, 58(1), 66 - 9 Partial characterization of a DNA restriction endonuclease from Ruminococcus flavefaciens FD-1 and its inhibition by site-specific adenine methylation; Morrison M et al.; The principal DNA restriction-modification system of the cellulolytic ruminal bacterium Ruminococcus flavefaciens FD-1 is described . The restriction endonuclease RflFI could be separated from cell extracts by phosphocellulose and heparin-sepharose chromatography . Restriction enzyme digests utilizing RflFI alone or in combination with SalI, a restriction enzyme isolated from Streptomyces albus G, showed that the DNA sequence recognized by RflFI either overlapped or was the same as that recognized by SalI . DNA sequence analysis confirmed that RflFI was identical in activity to SalI, with the recognition sequence being 5'-GTCGAC-3' and cleavage occurring between G and T . Adenine methylation within this sequence can be catalyzed in vitro by TaqI methylase, and this inhibited the cleavage of plasmid DNA molecules by RflFI and SalI . Chromosomal DNA from R . flavefaciens FD-1 is also methylated within this DNA sequence because neither restriction endonuclease could degrade this DNA substrate . These findings provide a means to protect plasmid molecules from degradation prior to gene transfer experiments with R . flavefaciens FD-1. Appl Environ Microbiol, 1992 Jan, 58(1), 157 - 68 Purification, characterization, and mode of action of endoxylanases 1 and 2 from Fibrobacter succinogenes S85; Matte A et al.; Two different endoxylanases (1,4-beta-D-xylan xylanohydrolases, EC 3.2.1.8), designated 1 and 2, have been purified by column chromatography to apparent homogeneity from the nonsedimentable extracellular culture fluid of the strictly anaerobic, ruminal bacterium Fibrobacter succinogenes S85 grown on crystalline cellulose . Endoxylanases 1 and 2 were shown to be basic proteins of 53.7 and 66.0 kDa, respectively, with different pH and temperature optima, as well as different substrate hydrolysis characteristics . The Km and Vmax values with water-soluble oat spelts xylan as substrate were 2.6 mg ml-1 and 33.6 mumol min-1 mg-1 for endoxylanase 1 and 1.3 mg ml-1 and 118 mumol min-1 mg-1 for endoxylanase 2 . Endoxylanase 1, but not endoxylanase 2, released arabinose from water-soluble oat spelts xylan and rye flour arabinoxylan, but not from arabinan, arabinogalactan, or aryl-alpha-L-arabinofuranosides . With an extended hydrolysis time, endoxylanase 1 released 62.5 and 50% of the available arabinose from water-soluble oat spelts xylan and rye flour arabinoxylan, respectively . Endoxylanase 1 released arabinose directly from the xylan backbone, and this preceded hydrolysis of the xylan to xylooligosaccharides . Endoxylanase 2 showed significant activity against carboxymethyl cellulose but was unable to substantially hydrolyze acid-swollen cellulose . Both enzymes were endo-acting, as revealed by their hydrolysis product profiles on water-soluble xylan and xylooligosaccharides . Because of their unique hydrolytic properties, endoxylanases 1 and 2 appear to have strategic roles in plant cell wall digestion by F . succinogenes in vivo. Scand J Clin Lab Invest Suppl, 1992, 210, 81 - 96 Clinical implications of serum pepsinogen and progastricsin in man; Axelsson CK; The serum pepsinogens in man have been reviewed with respect to clinical and physiological significance . The many places of synthesis of pepsinogen (PG A) and progastricsin (PG C) are described . The major part of serum pepsinogen and progastricsin is synthezized in the stomach, and the findings after antrectomy indicate that the majority of the pepsinogens in serum originates from the corpus of the stomach . The concentrations of pepsinogen and progastricsin in serum in relation to stomach diseases, e.g . ulcer disease, gastritis, and cancer of the stomach, are described . Despite typical findings, i.e . hyperpepsinogenemia in duodenal ulcer disease, or hypopepsinogenemia in atrophic gastritis or stomach cancer, there is a big overlap in serum concentrations between the groups reducing the clinical value of routine measurements of pepsinogens . Most promising are the findings in stomach cancer disease, where the combined measurement of pepsinogen levels and the isozymogen Pg5 is found to be highly indicative for the presence of a gastric carcinoma . Reports state that pepsinogens are excellent markers of recurrence of gastric cancer somewhere in the body after total gastrectomy . Genetical studies have--concerning pepsinogen--proved the multiple gene/multiple loci model . There is only a single progastricsin gene in humans and no genetic heterogenity has been found . Finally, the relationship between gastric infection with the bacterium Helicobacter pylori, and elevated pepsinogen and progastricsin levels in the blood, and the search for serologic markers of gastric diseases is discussed. Arch Microbiol, 1992, 158(4), 302 - 8 Characterization of a carbofuran-degrading bacterium and investigation of the role of plasmids in catabolism of the insecticide carbofuran; Head IM et al.; A bacterium capable of using the carbamate insecticide carbofuran as a sole source of carbon and energy, was isolated from soil . The ability to catabolise carbofuran phenol, produced by cleavage of the carbamate ester linkage of the insecticide, was lost at very high frequency when the bacterium was grown in the absence of carbofuran . Plasmid analyses together with curing and mating experiments indicated that the presence of a large plasmid (pIH3, greater than 199 kb) was required for the degradation of carbofuran phenol. Digestion, 1992, 51 Suppl 1, 70 - 5 Natural history of gastritis and its relationship to peptic ulcer disease; Sipponen P; Chronic gastritis is a common inflammatory disease . In a number of patients, the inflamed gastric mucosa shows a gradual tendency to become atrophic (atrophic gastritis) . Gastritis tends to be lifelong, and spontaneous healing is rare . With very few exceptions (e.g . in patients with autoimmune chronic corpus gastritis), gastritis is associated with the presence of the bacterium Helicobacter pylori . Inflammation and atrophy of the gastric mucosa result in impairment of gastric secretory functions (e.g . secretion of gastric acid, pepsin and gastrin) . Such impairment is dependent on the topographic type of gastritis; i.e . whether the inflammation and atrophy occur in the antrum (chronic antral gastritis), corpus (chronic corpus gastritis) or in both the antrum and corpus simultaneously (chronic pangastritis) . Gastritis of different topographic types associates with different gastric diseases . In patients with H . pylori-related antral or pangastritis, peptic ulcer disease, and in particular duodenal ulcer, is common (with an incidence exceeding 20% after 10 years' follow-up), as compared with peptic ulcer disease, which is very rare in patients with a normal stomach . Gastric ulcer may sometimes occur in patients with a rather atrophic stomach, but both gastric and duodenal ulcers are extremely rare in patients in whom the gastritis accompanies severe atrophic changes in the corpus mucosa . Routine biopsies from the antrum and corpus, and interpretation of the results in the light of the data on gastritis and its atrophic sequelae, allow the gastroenterologist to predict the risk and likelihood of peptic ulcer disease in patients with gastritis. Folia Microbiol (Praha), 1992, 37(2), 159 - 60 Abscisic acid and its synthetic analog in relation to growth and nitrogenase activity of Azotobacter chroococcum and Nostoc muscorum; Marsalek B et al.; The plant hormone abscisic acid as well as its synthetic analog LAB 173711 significantly increased the nitrogenase activity of the bacterium Azotobacter chroococcum and the cyanobacterium Nostoc muscorum . The effect depended on the concentration of the substances (0.001-10 mg/L) and the age of the cultures . The biomass of the organisms was not significantly influenced. Sci Prog, 1992, 76(301-302 Pt 3-4), 399 - 424 Pattern and control in bacterial colony development; Shapiro JA; As we learn more about bacterial life in the laboratory and in nature, we increasingly appreciate that they are highly sensitive and sophisticated organisms . One of the principal new insights has been the appreciation that bacteria are interactive and form organized, differentiated multicellular communities . Colonies produced on laboratory media by the standard research bacterium, Escherichia coli, are excellent examples . The organization of these colonies can be visualized in the microscope, by macrophotography, and by the use of special dyes and genetic engineering techniques to reveal patterns of differential gene expression . Observation of the dynamics of colony growth, and the response of colonies to experimental disruptions of normal development, indicate that control systems work to produce the regular patterns observed . The effects of obstacles and of other colonies on gene expression patterns indicate that non-linear responses to chemical gradients in the substrate play an important coordinating role in colony development. Arch Microbiol, 1992, 158(3), 226 - 33 The cytochrome composition of the meat spoilage bacterium Brochothrix thermosphacta: identification of cytochrome a3-and d-type terminal oxidases under various conditions; Gil A et al.; Brochothrix thermosphacta, grown in batch culture in a yeast-dextrose broth, at temperatures from 30 degrees C to 10 degrees C, contained diverse membrane-bound respiratory cytochromes . Under conditions of moderate aeration, cytochromes of the a-, b- and d-type were detected at all growth temperatures, but the proportions changed as a function of temperature, with the spectra of cells grown at 10 or 15 degrees C being dominated by a-type cytochrome(s) . Cytochrome a3 was detected by its reactions with CO and cyanide in cells from all growth conditions . An additional cytochrome a, which was not cyanide-reactive, was also detected, suggesting the presence of an aa3 oxidase complex . Cytochrome d was cyanide- and CO-reactive, but not detectable in photodissociation spectra, presumably because of the very rapid recombination of CO at the sub-zero temperatures used . Decreasing the oxygen transfer rates to batch cultures resulted in enhanced expression of cytochrome d and changed the proportion of the aa3-type oxidase that could be attributed to ligand-binding cytochrome a3; at the lowest oxygen transfer rates, no cytochrome a was detected, suggesting the presence of a cytochrome ba3 terminal oxidase complex . Intact cells showed no evidence of a c-type cytochrome and no haem C was detected in membrane preparations . After growth at 10 degrees C, the cytochrome composition of B . campestris was essentially identical to that of B . thermosphacta . The multiplicity of putative terminal oxidases in B . thermosphacta is discussed. Arch Biochem Biophys, 1992 Jan, 292(1), 29 - 33 NADH-dependent methemoglobin reductase from the obligate aerobe Vitreoscilla: improved method of purification and reexamination of prosthetic groups; Jakob W et al.; The NADH-dependent methemoglobin reductase from the bacterium Vitreoscilla was purified using hydrophobic chromatography on a phenyl-Sepharose column . The new procedure resulted in a purer protein and increased the overall yield of the enzyme by a factor of approximately three . The active site of the enzyme was investigated by ultraviolet/visible, fluorescence, Mossbauer, and electron paramagnetic resonance spectroscopy (EPR) at 9.4 GHz . Prosthetic group analysis revealed the presence of one FAD per active enzyme molecule but no iron in contrast to earlier reports . The NADH-methemoglobin reductase activity of the pure enzyme was in the range of 1.1-1.25 units; its electronic and fluorescence spectra were typical of metal-free flavoproteins . No EPR signals were detected between 5 and 150 K over a field range 0.05-0.5 T, and there was no Mossbauer signal, consistent with the absence of iron . Methemoglobin reductase from Vitreoscilla was reduced by dithionite, NADH, and deazaflavin/EDTA upon illumination . The main species observed during these anaerobic oxidation-reduction experiments was the blue semiquinone radical with an EPR signal at g = 2.005, linewidth 1.5 mT . The fully reduced state of the enzyme, FlredH3, was also observed in the reaction with NADH . The reduction was fully reversible with ferricyanide . The observations reported here are consistent with a redox enzyme interacting both with a two-electron donating agent such as NADH and a one-electron accepting center such as the Fe(III)/Fe(II) couple of Vitreoscilla hemoglobin. Arch Biochem Biophys, 1992 Jan, 292(1), 102 - 6 Sodium-coupled ATP synthesis in the bacterium Vitreoscilla; Efiok BJ et al.; The bacterium Vitreoscilla generates an electrical potential gradient due to sodium ion (delta psi Na+) across its membrane via respiratory-driven primary Na+ pump(s) . The role of the delta psi Na+ as a driving force for ATP synthesis was, therefore, investigated . In respiring starved cells pulsed with 100 mM external Na+ {( Na+}o) there was a 167% net increase in cellular ATP concentration over basal levels compared with 0, 56, 78, and 78% for no addition, choline, Li+, and K+ controls, respectively . Doubling the {Na+}o to 200 mM boosted the net increase to 244% but a similar doubling of the choline caused only an increase to 78% . When the initial condition was intracellular Na+ ({Na+}i) = {Na+}o = 100 mM, there was a 94% net increase in cellular ATP compared with only 18 and 11% for Li+ and K+ controls, respectively, indicating that Nai+ may be the only cation tested that the cells extruded to generate the electrochemical gradient required to drive ATP synthesis . The Na(+)-dependent ATP synthesis was inhibited completely by monensin (12 microM), but only transiently by the protonophore 3,5-di-tert-butyl-4-hydroxybenzaldehyde (100 microM), further evidence that the Na+ gradient and not a H+ gradient was driving the ATP synthesis . ATP synthesis in response to an artificially imposed H+ gradient (delta pH approximately 3) in the absence of an added cation, or in the presence of Li+, K+, or choline, yielded similar delta ATP/delta pH ratios of 0.98-1.22 . In the presence of Na+, however, this ratio dropped to 0.23, indicating that Na+ inhibited H(+)-coupling to ATP synthesis and possibly that H+ and Na+ coupling to ATP synthesis share a common catalyst . The above evidence adds to previous findings that under normal growth conditions Na+ is probably the main coupling cation for ATP synthesis in Vitreoscilla. Microbiol Immunol, 1992, 36(9), 983 - 97 DNA from bacteria, but not from vertebrates, induces interferons, activates natural killer cells and inhibits tumor growth; Yamamoto S et al.; The nucleic acid fraction from cells of 6 species of bacterium and 2 kinds of vertebrate, calf and salmon, was extracted and purified by the same procedures as described previously . When the spleen cells from BALB/c mice were incubated with the nucleic acid fraction from either of the bacteria, natural killer (NK) activity of the cells was remarkably elevated and the cells produced factors to activate macrophages and to inhibit viral growth . It was shown that the factor to activate macrophages was interferon (IFN)-gamma and that to inhibit viral growth was IFN-alpha/beta . On the other hand, the nucleic acid fraction from either of the vertebrate cells did not show such activities . Pretreatment of the bacterial nucleic acid fraction with DNase, but not with RNase, abrogated completely the biological activities . The activities of the bacterial nucleic acid were not influenced by the presence of polymyxin B, an inhibitor of lipopolysaccharide (LPS), and the spleen cells from not only BALB/c mice but also LPS-insensitive C3H/HeJ mice were activated, indicating that the activities of the fraction were not ascribed to LPS contaminated possibly into the fraction, but to DNA itself . Intralesional injection with the bacterial DNA fraction caused regression of mouse IMC tumors, but the injection with the vertebrate DNA fraction did not . These findings prompted us to examine the biological activities of DNA samples from a variety of animals and plants, which were provided from other laboratories or purchased from manufacturers . All of the DNA samples from cells of 5 kinds of bacterium, 2 of virus and 4 of invertebrate augmented NK activity and induced IFN, more or less, in mouse spleen calls, while the DNA from 10 kinds of vertebrate, including 3 of fish and 5 of mammal, showed no such activities . The DNA from 2 species of plants, were also inactive . Possible mechanisms to explain the different biological activities of DNA from different cell sources were discussed based on our previous finding that the particular palindromic sequences with a G-C motif(s) are required for induction of IFNs and activation of NK cells with synthetic 30-mer oligonucleotides. Ann N Y Acad Sci, 1991 Dec 27, 646, 99 - 105 Transformation of a methylotrophic bacterium, Methylobacterium extorquens, with a broad-host-range plasmid by electroporation; Ueda S et al.; Electroporation was used to transform the methylotrophic bacterium Methylobacterium extorquens with broad-host-range plasmid pLA2917, which contains a gene specifying resistance to kanamycin . Plasmid DNA was introduced into M . extorquens in the presence of an electric pulse, and kanamycin-resistant transformants were obtained . These transformants harbored plasmid DNA that was identical to plasmid pLA2917 . We examined several factors independently and found up to 8 x 10(3) transformants per microgram of DNA using 10 pulses with a duration of 300 microseconds at a field strength of 10 kV/cm. Ann N Y Acad Sci, 1991 Dec 27, 646, 53 - 60 Construction and evaluation of a self-luminescent biosensor; Geiselhart L et al.; The genes encoding bioluminescence (lux genes), derived from the marine bacterium V . fischeri, have been fused next to the genes encoding mercury detoxification (mer genes), derived from a clinical isolate of S . marcescens . The fusion has been made so that the expression of the light genes comes under the control of the mer regulatory gene and promoter . These genetic elements activate the expression of the light genes in the presence of mercury . The light can readily be collected and quantitated, resulting in a biosensor for the detection of mercury. Gene, 1991 Dec 20, 109(1), 55 - 61 Molecular analysis of the dmpM gene encoding an O-demethyl puromycin O-methyltransferase from Streptomyces alboniger; Lacalle RA et al.; The nucleotide (nt) sequence of a 1332-bp fragment of Streptomyces alboniger DNA containing the gene (dmpM), which encodes an O-demethyl puromycin O-methyltransferase (DMPM), has been determined . The dmpM gene contains a 1131-nt open reading frame which encodes a polypeptide of Mr 40,303; this is consistent with the 44 +/- 2.5- and 160-kDa sizes of the DMPM monomer and its native form, respectively . The ATG start codon of dmpM is 50 bp downstream from the coding sequence of the gene (pac), which determines a puromycin N-acetyltransferase . S1 mapping experiments indicate that pac and dmpM are transcribed on a single transcript, which ends at least 500 nt downstream from the dmpM stop codon . The deduced amino acid sequence of DMPM shows significant similarities to those of a hydroxyindole O-methyltransferase, which is involved in the biosynthesis of melatonin by bovine pineal glands {Ishida et al., J . Biol . Chem . 262 (1987) 2895-2899}, a hydroxyneurosporene methyltransferase, which is involved in carotenoid biosynthesis in the purple nonsulfur bacterium, Rhodobacter capsulatus {Armstrong et al., Mol . Gen . Genet . 216 (1989) 254-268} and two O-methyltransferases of the tetracenomycin biosynthesis pathway from Streptomyces glaucescens. Gene, 1991 Dec 20, 109(1), 131 - 6 Characterization of melA: a gene encoding melanin biosynthesis from the marine bacterium Shewanella colwelliana; Fuqua WC et al.; A recombinant plasmid with the ability to impart melanin synthesis to an Escherichia coli host was isolated from a Shewanella colwelliana genomic library . The genetic determinant of the Mel+ phenotype is carried on a 1.3-kb DNA fragment and sequence analysis of this revealed a single intact open reading frame that was sufficient for melanin synthesis (mel) . This gene is expressed as a monocistronic transcript and a putative transcription start point is located 115 nucleotides upstream from the translational start codon . The mel gene encoded a protein of 39.5 kDa {346 amino acids (aa)} that showed no aa sequence homology with other proteins known to mediate melanin synthesis (e.g., tyrosinases). FEBS Lett, 1991 Dec 16, 295(1-3), 119 - 22 A sodium-stimulated ATP synthase in the acetogenic bacterium Acetobacterium woodii; Heise R et al.; Experiments with resting cells of Acetobacterium woodii were performed to elucidate the coupling ion used by the ATP synthase . A . woodii synthesized ATP in response to an artificial delta pH, indicating the presence of a proton-translocating ATPase . On the other hand, a delta pNa, as well as a proton diffusion potential, could serve as a driving force for ATP synthesis with the latter strictly dependent on Na+ . These results are indicative for the presence of a Na(+)-translocating ATP synthase in A . woodii. Biochemistry, 1991 Dec 3, 30(48), 11451 - 8 The primary structure of cytochrome c-554 from the green photosynthetic bacterium Chloroflexus aurantiacus; Dracheva S et al.; The complete nucleotide sequence of the cytochrome c-554 gene from the green photosynthetic bacterium Chloroflexus aurantiacus has been determined . The derived amino acid sequence showed that the cytochrome precursor protein consists of 414 residues and contains 4-Cys-X-X-Cys-His- heme binding motifs . The only regions of the cytochrome c-554 sequence that were found to be significantly similar to the sequences of cytochromes from other organisms were the heme binding sites . The highest similarity was found with the heme binding segments in the four-heme reaction center cytochrome subunit from the purple photosynthetic bacterium Rhodopseudomonas viridis . The importance of this similarity for the evolutionary relationship between Chloroflexus and the purple bacteria is discussed. Biochim Biophys Acta, 1991 Dec 2, 1129(1), 112 - 4 A bacterial homolog to HPRT; Beckman DL et al.; The deduced 182 amino acid sequence of an open reading frame in the photosynthetic bacterium Rhodobacter capsulatus shows significant similarity to the hypoxanthine-guanine phosphoribosyltransferases of other organisms . This similarity includes conserved amino acid residues involved in Lesch-Nyhan syndrome. Proc Natl Acad Sci U S A, 1991 Dec 1, 88(23), 10749 - 53 A mutation in a Rhodobacter capsulatus gene encoding an integration host factor-like protein impairs in vivo hydrogenase expression; Toussaint B et al.; A gene capable of encoding a protein sharing 45% identical amino acids with the alpha subunit of the integration host factor (IHF) of Escherichia coli was isolated from the photosynthetic bacterium Rhodobacter capsulatus strain B10 by complementation of a hydrogenase-deficient (Hup-) mutant, IR4 . A DNA fragment of 274 base pairs containing an IHF binding consensus sequence, isolated from the promoter region of the hydrogenase structural genes (hupSL), was shown by gel retardation assays to bind the IHF protein from E . coli . The product of the R . capsulatus gene was shown to bind specifically to the 274-base-pair DNA fragment from the hupSL promoter . By analogy to the E . coli himA gene, which encodes the alpha subunit of IHF, the gene complementing the IR4 mutant was named himA of R . capsulatus . The wild-type himA gene, cloned in plasmid pBO2, was introduced into the IR4 strain and shown to restore, in trans, hydrogenase activity and autotrophic growth in the mutant . In IR4, a C----T transition mutation had replaced Arg-8 by Cys-8 . Gel mobility shifts of the 274-base-pair DNA fragment, not observed with the himA gene product of IR4, were restored with extracts from IR4(pBO2) cells, containing the himA gene on the recombinant plasmid pBO2. Proc Natl Acad Sci U S A, 1991 Dec 1, 88(23), 10387 - 91 Expression and assembly of spectrally active recombinant holophytochrome; Wahleithner JA et al.; To develop an in vitro phytochrome assembly system, we have expressed an oat phytochrome cDNA in both the yeast Saccharomyces cerevisiae and the bacterium Escherichia coli . Analysis of soluble protein extracts showed that the recombinant apophytochromes were full-length and capable of covalently attaching the phytochrome chromophore analogue phycocyanobilin . Difference spectra indicated that in vitro-assembled holophytochrome species were photoreversible; however, maxima and minima difference absorption values were blue-shifted relative to those of the native photoreceptor . Extracts containing the recombinant apophytochromes were also incubated with phytochromobilin, the natural chromophore synthesized from biliverdin by cucumber etioplast preparations . In these experiments, the difference spectrum obtained was identical to that of native oat holophytochrome . These results suggest that the recombinant apophytochromes adopt a structure similar to that of the apoprotein biosynthesized in vivo . ELISAs were used to quantitate phytochrome expression levels in both yeast and E . coli extracts . These measurements show that 62-75% of the phytochrome apoprotein in the soluble protein extract was competent to assemble with bilins to form spectrally active holophytochrome. J Bacteriol, 1991 Dec, 173(23), 7607 - 14 Defects in gliding motility in mutants of Cytophaga johnsonae lacking a high-molecular-weight cell surface polysaccharide; Godchaux W 3rd et al.; We previously observed (W . Godchaux, L . Gorski, and E.R . Leadbetter, J . Bacteriol . 172:1250-1255, 1990) that two mutants (strains 21 and NS-1) of the gliding bacterium Cytophaga johnsonae that were totally deficient in motility-dependent colony spreading, movement of rafts (groups) of cells as observed with a microscope, and movement of polystyrene-latex spheres that attached to the cell surface (observed in wet mounts) were also deficient in a high-molecular-weight cell surface polysaccharide (HMPS) and suggested a role for that substance in gliding motility . Antisera have been prepared against the purified HMPS, and these were used to select mutants specifically and highly deficient in the polysaccharide . All five such mutants had rates of colony spreading and raft movement that were much lower than those of the parent strain, but the rate of increase in colony diameter was higher than that found for strains NS-1 and 21 (which do not undergo raft movement at all) . Unlike these latter two strains, the HMPS mutants retained the ability to move polystyrene-latex spheres over their surfaces . Hence, HMPS deficiency results in defective motility but not nonmotility, and the HMPS deficiency cannot fully explain the phenotype of mutants 21 and NS-1; in these strains, gliding must be affected by additional biochemical lesions . The HMPS may, nonetheless, be advantageous in that it supports greater gliding speeds. FEMS Microbiol Immunol, 1991 Dec, 4(1), 51 - 6 Association of Lps gene with natural resistance of mouse macrophages against Legionella pneumophila; Yoshida S et al.; Peritoneal macrophages obtained from lipopolysaccharide (LPS)-low responder C3H/HeJ mice (J) permitted the intracellular growth of the bacterium in macrophages of (J x N) F1 progeny was between the parent strains, showing that the traits were co-dominantly expressed . Correlation between intracellular bacterial growth in macrophages and LPS response of spleen cells was examined . Negative correlation was found between the two factors in F2, (J x F1) backcross and (N x F1) backcross progeny . This result implies that Lps gene controls the innate resistance of murine macrophages against the bacteria . Although macrophages of A/J strain also permit intracellular growth of L . pneumophila, gene complementation analysis of A/J and C3H/HeJ mice made clear that the gene control in C3H/HeJ differs from that of A/J strain . Macrophages of C57BL/10ScN, which is LPS-low responder line obtained from C57BL/10, were also defective in controlling the bacterial growth when compared to C57BL/10 mice . We suggest that the Lps gene also controls the natural resistance of murine macrophages against L . pneumophila. Mol Microbiol, 1991 Dec, 5(12), 3055 - 62 Purification, characterization and nucleotide sequence of the periplasmic C4-dicarboxylate-binding protein (DctP) from Rhodobacter capsulatus; Shaw JG et al.; A periplasmic binding protein essential for high-affinity transport of the C4-dicarboxylates malate, succinate and fumarate across the cytoplasmic membrane of the purple photosynthetic bacterium Rhodobacter capsulatus has been purified to homogeneity and some of its ligand-binding properties characterized . The protein was not produced in a Tn5 insertion mutant unable to transport C4-dicarboxylates under aerobic conditions in the dark . Wild-type DNA corresponding to the location of the transposon insertion site was subcloned and a 1.5 kb section sequenced . A complete open reading frame of 999 bp was identified that encoded a 333-residue protein (DctP) with a molecular weight of 36,128 with a 26-residue amino-terminal signal peptide . The identify of this protein with the purified dicarboxylate-binding protein and the position of the predicted signal peptide cleavage site was confirmed by N-terminal sequencing . No significant homology with other proteins was detected in database searches . A GC-rich region of dyad symmetry was located 7 bp downstream of the dctP translational stop codon . This structure may be of significance in regulating the relative abundance of DctP and other dct gene products which comprise the high-affinity dicarboxylate transport system in this bacterium. J Gen Microbiol, 1991 Dec, 137 ( Pt 12), 2839 - 43 Escherichia coli metabolism in space; Bouloc P et al.; Cultures of the bacterium Escherichia coli were grown in the orbiting Biocosmos 2044 satellite in order to evaluate the effects of the space environment--weightlessness and heavy particle radiation--on growth parameters and energy metabolism, which have previously been reported to be affected, and on induction of the SOS response, which reflects DNA damage to the cell . We found no differences between the flight samples and control ground cultures in the growth yield per gram of carbon, in mean cell mass (from which we deduce that the growth rate was unaltered) or in the level of expression of the SOS response . These observations indicate that free-growing bacterial cells do not expend significant energy fighting gravity and that cosmic radiation within a space capsule does not produce significant levels of DNA damage. J Med Microbiol, 1991 Dec, 35(6), 345 - 8 Histopathological study of porcine gastric mucosa with and without a spiral bacterium ("Gastrospirillum suis"); Mendes EN et al.; Tightly spiralled bacteria ("Gastrospirillum suis") were seen in the pyloric mucosa of the stomach of 13 (10.8%) of 120 pigs that appeared clinically healthy at slaughter and in the fundic mucosa of three (5.0%) out of 60 pigs . The spiral organism could not be cultured from any pig . Chronic gastritis was observed in the pyloric mucosa of 53 (44.2%) of 120 pigs and in the fundic mucosa of 7 (11.7%) of 60 pigs . The 13 pigs with spiral bacteria in the pyloric region comprised one animal (7.7%) with normal pyloric mucosa, two (15.4%) with "borderline gastritis", and 10 (76.9%) with chronic gastritis--in one instance accompanied by signs of activity (numerous polymorphonuclear cells) . The three pigs with spiral bacteria in the fundic mucosa comprised two animals with a normal fundic region and one with "borderline gastritis" . The presence of the spiral bacterium was significantly associated with pyloric gastritis (p = 0.013) and with numbers of lymphoid follicles (p = 0.014). J Bacteriol, 1991 Dec, 173(24), 7925 - 33 Characterization of the haloacid dehalogenase from Xanthobacter autotrophicus GJ10 and sequencing of the dhlB gene; van der Ploeg J et al.; The haloacid dehalogenase of the 1,2-dichloroethane-utilizing bacterium Xanthobacter autotrophicus GJ10 was purified from a mutant with an eightfold increase in expression of the enzyme . The mutant was obtained by selecting for enhanced resistance to monobromoacetate . The enzyme was purified through (NH4)2SO4 fractionation, DEAE-cellulose chromatography, and hydroxylapatite chromatography . The molecular mass of the protein was 28 kDa as determined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 36 kDa as determined with gel filtration on Superose 12 fast protein liquid chromatography . The enzyme was active with 2-halogenated carboxylic acids and converted only the L-isomer of 2-chloropropionic acid with inversion of configuration to produce D-lactate . The activity of the enzyme was not readily influenced by thiol reagents . The gene encoding the haloacid dehalogenase (dhlB) was cloned and could be allocated to a 6.5-kb EcoRI-BglII fragment . Part of this fragment was sequenced, and the dhlB open reading frame was identified by comparison with the N-terminal amino acid sequence of the protein . The gene was found to encode a protein of 27,433 Da that showed considerable homology (60.5 and 61.0% similarity) with the two other haloacid dehalogenases sequenced to date but not with the haloalkane dehalogenase from X . autotrophicus GJ10. Am Rev Respir Dis, 1991 Dec, 144(6), 1408 - 10 Chlamydia pneumoniae, strain TWAR, infection in patients with chronic obstructive pulmonary disease; Beaty CD et al.; TWAR, the only known serovar of Chlamydia pneumoniae, is a newly described bacterium that has been identified as a cause of both epidemics and endemic cases of pneumonia . The role of TWAR infection in patients with chronic obstructive pulmonary disease (COPD) is not known . We conducted a prospective study to establish whether TWAR infection is a common cause of acute exacerbations of COPD . We studied two groups of patients: 44 patients admitted to the hospital with acute exacerbations of COPD, and 65 stable clinic patients with COPD . We found that evidence of acute TWAR infection was infrequent in patients with exacerbations (5%) . In contrast, the majority of patients from both groups had serologic evidence of previous TWAR infection (77%) . This was not significantly greater than the prevalence found in a small group of patients of similar age and sex without lung disease from the same institution (73%) . TWAR was not isolated from the oropharyngeal specimens obtained from 97 subjects, suggesting that it does not colonize the respiratory tract of patients with COPD . This study shows that at the time of low incidence in the community, acute TWAR infection is uncommon in patients with acute exacerbations of COPD . The majority of patients with COPD have, however, been infected with TWAR in the past . The clinical manifestations of these infections are not known and should be the focus of further studies. Oral Microbiol Immunol, 1991 Dec, 6(6), 356 - 62 Phenotypic analysis of B-cells extracted from human periodontal disease tissue; Gemmell E et al.; B-cells extracted from periodontal disease tissue were analyzed for the presence of activation markers using a range of monoclonal antibodies . In adult periodontitis (AP), 6% of B-cells expressed the IL-2 receptor (CD25) compared with 1-2% in peripheral blood and healthy or marginal gingivitis (H/MG) gingival B-cells . There was also an increase in the mean percentage of IgD-positive B-cells and a decrease in CD21 and CD22 expression . In both AP and H/MG lesions, 20-22% of the B-cells expressed CD23 compared with less than 5% in peripheral blood . As B-cells are activated by day 3 in culture and start differentiating into immunoglobulin-secreting cells by day 6, B-cell phenotypes were assayed at these times in this study . Following stimulation with the periodontopathic bacterium Porphyromonas gingivalis, the expression of CD23, CD21 and CD22 on B-cells extracted from AP lesions remained relatively constant over the 6-d culture period . However, with Fusobacterium nucleatum stimulation, there was a significant decrease in CD23, CD21 and CD22 expression after 3 d in culture, which corresponds to the activation time for B-cells . These results show that B-cells extracted from periodontal disease tissue display a range of activation markers and on stimulation, demonstrate differing responses to individual periodontopathic bacteria. Toxicol Appl Pharmacol, 1991 Dec, 111(3), 485 - 95 The evaluation of Escherichia coli as a model for oxidant stress in mammalian hepatocytes: role of glutathione; Romero MJ et al.; Among bacteria, Escherichia coli are unique because they contain an amount of glutathione (GSH) comparable to that of mammalian cells . Thus, this bacterium has been suggested as a model for oxidant stress in mammalian systems . Two common strains of E . coli, ATCC 29682, a B strain, and AB 1157, a K-12 strain, were exposed to paraquat (PQ) or t-butyl hydroperoxide (TBH) and the effect on GSH, growth, and lethality was assessed . Exposure of both strains to 5 mM PQ resulted in an 80% decrease in GSH . Exposure to 5 mM TBH resulted in a 31% decrease in GSH in the K-12 strain and an 80% decrease in the B strain . No correlation was found between the GSH decrease in either strain and the PQ or TBH growth inhibitory effects . TBH exposures increased oxidized GSH (GSSG) export . However, no increase in intracellular GSSG or protein-mixed disulfides was found after exposure to either oxidant nor was GSSG secreted following PQ . After failing to inhibit GSH synthesis with buthionine sulfoximine, a B strain GSH-deficient mutant {RCI-1} was constructed . There was no difference in the growth and lethality responses to the oxidants between GSH-deficient and -sufficient strains . GSH supplementation with N-acetylcysteine or L-2-oxothiazolidine decreased the sensitivity of the E . coli B strain to the growth inhibitory but not the lethality effects of TBH . The lack of a correlation of changes in GSH with either oxidant-induced growth inhibitory or lethality effects, the presence of catalase in the cytoplasm not peroxisomes, and the absence of glutathione peroxidase are limitations to the value of this bacterium as a model for mammalian oxidant stress. Biochemistry, 1991 Nov 19, 30(46), 11118 - 23 Cloning and sequencing of the gene for rubrerythrin from Desulfovibrio vulgaris (Hildenborough); Prickril BC et al.; The gene coding for rubrerythrin from the sulfate-reducing bacterium Desulfovibrio vulgaris (Hildenborough) has been cloned and sequenced . Rubrerythrin is known to contain two types of iron sites: one rubredoxin-like FeS4 center in each of the two identical subunits and one hemerythrin-like diiron site per dimer {LeGall, J., et al . (1988) Biochemistry 27, 1636-1642} . The gene encodes a polypeptide of 191 amino acids, and a normal ribosome binding site is located 11-6 base pairs upstream from the translational start of the gene . There is no evidence for the presence of a leader sequence, suggesting a cytoplasmic location for the protein . The rubrerythrin gene is not part of any other known transcriptional unit in the D . vulgaris genome . The nucleotide sequence encodes four Cys residues, the minimum required for ligation to iron in rubredoxin . The pairs of Cys residues occur in Cys-X-X-Cys sequences as they do in rubredoxin, but the 12-residue spacing between the Cys pairs in rubrerythrin is less than half that in rubredoxins . A pair of Arg residues flanking one Cys residue may contribute to the much more positive reduction potential of the rubredoxin-like site in rubrerythrin compared to that of rubredoxin . While the amino acid sequence of rubrerythrin shows no significant overall homology with that of any known protein, the C-terminal region does share some homology with rubredoxin sequences . If folding of the rubredoxin-like amino acid sequence domain in rubrerythrin is similar to that in rubredoxins, then three His residues are brought into proximity.(ABSTRACT TRUNCATED AT 250 WORDS) Science, 1991 Nov 29, 254(5036), 1374 - 7 The N-end rule in bacteria; Tobias JW et al.; The N-end rule relates the in vivo half-life of a protein to the identity of its amino-terminal residue . Distinct versions of the N-end rule operate in all eukaryotes examined . It is shown that the bacterium Escherichia coli also has the N-end rule pathway . Amino-terminal arginine, lysine, leucine, phenylalanine, tyrosine, and tryptophan confer 2-minute half-lives on a test protein; the other amino-terminal residues confer greater than 10-hour half-lives on the same protein . Amino-terminal arginine and lysine are secondary destabilizing residues in E . coli because their activity depends on their conjugation to the primary destabilizing residues leucine or phenylalanine by leucine, phenylalanine-transfer RNA-protein transferase . The adenosine triphosphate-dependent protease Clp (Ti) is required for the degradation of N-end rule substrates in E . coli. J Biol Chem, 1991 Nov 5, 266(31), 20645 - 53 The primary structure of rubrerythrin, a protein with inorganic pyrophosphatase activity from Desulfovibrio vulgaris . Comparison with hemerythrin and rubredoxin; Van Beeumen JJ et al.; The complete polypeptide chain of rubrerythrin from the sulfate reducing bacterium Desulfovibrio vulgaris, strain Hildenborough NCIB 8303, was found by protein chemical techniques to consist of 191 residues and to have the amino acid sequence {sequence: see text} The C-terminal part of the protein (position 153----191) shows the typical sequence features of rubredoxin, a protein with a nonheme iron center also present in the same and other Desulfovibrio species . Based on the known three-dimensional structure of D . desulfuricans rubredoxin, we propose that the C-terminal part of rubrerythrin is folded in a similar way and suggest that the deletion of the extra 10 residues is compatible with the same basic rubredoxin-fold . After characterization of the C-terminal region, and in contrast to what could be expected from previously published spectroscopic analyses, the N-terminal region 1-152 of rubrerythrin appears to have no sequence similarity with the eukaryotic protein hemerythrin which is known to contain a binuclear iron center bound by 5 histidine ligands . However, the N-terminal region of rubrerythrin does contain 5 histidine residues but they are differently spaced along the peptide chain . We suggest that at least one of the 3 histidine residues located in the rubredoxin-like center of rubrerythrin may be liganded to one iron atom of the hemerythrin-like center . This paper is the first sequence report of a protein with pyrophosphatase activity although the physiological substrate for the rubrerythrin may be not inorganic pyrophosphate. FEBS Lett, 1991 Nov 4, 292(1-2), 85 - 9 Isolation and nucleotide sequence of the Thiobacillus ferrooxidans genes for the small and large subunits of ribulose 1,5-bisphosphate carboxylase/oxygenase; Pulgar V et al.; The genes encoding for the large (rbcL) and small (rbcS) subunits of ribulose-1,5-bisphosphate carboxylase (RuBisCO) were cloned from the obligate autotroph Thiobacillus ferrooxidans, a bacterium involved in the bioleaching of minerals . Nucleotide sequence analysis of the cloned DNA showed that the two coding regions are separated by a 30-bp intergenic region, the smallest described for the RuBisCO genes . The rbcL and rbcS genes encode polypeptides of 473 and 118 amino acids, respectively . Comparison of the nucleotide and amino acid sequences with those of the genes for rbcL and rbcS found in other species demonstrated that the T . ferrooxidans genes have the closest degree of identity with those of Chromatium vinosum and of Alvinoconcha hessleri endosymbiont . Both T . ferrooxidans enzyme subunits contain all the conserved amino acids that are known to participate in the catalytic process or in holoenzyme assembly. J Protozool, 1991 Nov-Dec, 38(6), 573 - 6 Splenomegaly and reticulocytosis caused by Babesia microti infections in natural populations of the montane vole, Microtus montanus; Watkins RA et al.; A survey for Babesia microti in rodents was conducted at six sites within Grand Teton National Park, Wyoming . Blood and spleen smears, hematocrits, and reticulocyte counts were made on all of the animals to evaluate parameters for the diagnosis of babesiosis . Ticks were removed for identification . Of 257 Microtus montanus, 103 were infected with B . microti . In addition, five of 12 Microtus pennsylvanicus and one of three Arvicola richardsoni were parasitized by B . microti . Peromyscus maniculatus (n = 40) were not infected . Concurrent infections by Hepatozoon sp., Trypanosoma sp., and the bacterium, Grahamella sp., were noted in blood smears from a number of M . montanus . Splenomegaly and reticulocytosis were significant parameters associated with babesiosis while decreased hematocrit was not . Ticks removed from the voles were identified as Ixodes eastoni and were the probable vectors of the B . microti. J Cell Sci, 1991 Nov, 100 ( Pt 3), 613 - 22 Characterisation of potential adhesins of the bacterium Pasteuria penetrans, and of putative receptors on the cuticle of Meloidogyne incognita, a nematode host; Persidis A et al.; Pasteuria penetrans spores were fragmented by glass bead vortexing, producing exosporial membranes and spore fragments, which consisted of fibre bundles . Both exosporia and spore fragments are capable of host-specific attachment to the cuticle of Meloidogyne incognita, a root-knot nematode host . Putative M . incognita receptors appear to be soluble in beta-mercaptoethanol (BME) but not SDS, and are also sensitive to tryptic digestion and deglycosylation by endoglycosidase F . Polyclonal antibodies against intact spores and spore fragments of antispore antibodies produced 100% inhibition . The antibodies, however, did not show preferential staining of particular spore structures in thin section immunolabelling studies . Exposure of Pasteuria penetrans spores to HCl or urea-SDS-dithiothreitol renders them incapable of attachment to their host juveniles and extensively disrupts fibres that surround the spore core . Protein extracts from spore fragments or from exosporial membranes are identical, and urea-BME extracts from either structure, but not SDS extracts, can inhibit the attachment of spores to juveniles by 60-80% . An inhibitory BME extract from spore fragments was analysed by anion-exchange chromatography and adsorption onto host cuticle followed by immunoblotting . It appeared to contain six potential spore adhesins of approximate Mr 24-29, 38-47, 59, 89, 126, and 190 (x10(3)) . Lectin affinity blotting with wheat germ agglutinin and concanavalin A showed that all of these proteins bear terminal N-acetylglucosamine residues and the 38-47 kDa band also bears terminal Glc/Man residues.(ABSTRACT TRUNCATED AT 250 WORDS) Res Microbiol, 1991 Nov-Dec, 142(9), 1005 - 12 1,8-Naphthalic anhydride antidote enhances the toxic effects of captan and thiram fungicides on Azospirillum brasilense cells; Gallori E et al.; The effects of ten fungicides, six herbicides and four insecticides on the nitrogen-fixing bacterium Azospirillum brasilense were examined . The fungicides captan and thiram were the most toxic among the compounds tested . Cell growth and nitrogenase activity of the bacterium were markedly inhibited by low concentrations of the two fungicides . Antidote 1,8-naphthalic anhydride increased by a factor of 2 the cellular level of glutathione . The addition of the antidote in the presence of captan or thiram caused a similar increase in the glutathione content, but at the same time enhanced the toxicity of the two fungicides. J Clin Microbiol, 1991 Nov, 29(11), 2535 - 8 Actinobacillus spp . and related bacteria in infected wounds of humans bitten by horses and sheep; Peel MM et al.; We describe the isolation of Actinobacillus lignieresii and an A . equuli-like bacterium from an infected horse-bite wound in a 22-year-old stable foreman and A . suis from a bite injury in a 35-year-old man who had been attacked by a horse . A . lignieresii was also isolated in pure culture from an infected sheep-bite wound in a rural worker . These species of the genus Actinobacillus are primarily associated with animals and animal diseases and are rarely isolated from humans . The purpose of this report is to raise awareness of the possible occurrence of Actinobacillus spp . in bite wounds inflicted by farm animals and to discuss the difficulties encountered in the identification of species of Actinobacillus and related bacteria. Immunology, 1991 Nov, 74(3), 497 - 503 Growth inhibition of tumour cells by a liposome-encapsulated, mycolic acid-containing glycolipid, trehalose 2,3,6'-trimycolate; Ohtsubo Y et al.; In vivo growth of syngeneic tumour cells in the peritoneal cavity was strongly inhibited by intraperitoneal injection of a liposome-encapsulated, mycolic acid-containing glycolipid, trehalose 2,3,6'-trimycolate (TTM), derived from a non-pathogenic, acid-fast bacterium . Gordona aurantiaca . Peritoneal macrophages from mice after this treatment lysed tumour cells in vitro at a low effector/target ratio, and their culture supernatant inhibited tumour cell growth . The supernatant inhibited growth of not only tumour necrosis factor (TNF)-sensitive tumour cells, but also TNF-insensitive tumour cells . This inhibitory activity was enhanced by addition of lipopolysaccharide (LPS) to the culture medium of the macrophages . The macrophages released more superoxide (O2-), TNF and interleukin-1 (IL-1) on LPS triggering, and the releases of these compounds were further increased by addition of recombinant interferon-gamma (IFN-gamma) to the medium . Moreover, splenic T cells of TTM liposome-primed mice were found to produce eight times more IFN-gamma upon stimulation with LPS . These results indicated that priming with TTM liposomes resulted in strong activation of macrophages, which lysed tumour cells directly and also inhibited tumour cell growth by released factors. J Anim Sci, 1991 Nov, 69(11), 4628 - 33 Effect of a Saccharomyces cerevisiae culture on lactate utilization by the ruminal bacterium Selenomonas ruminantium; Nisbet DJ et al.; The objective of this study was to examine the effects of a Saccharomyces cerevisiae culture (YEA-SACC) on lactate utilization by the predominant ruminal bacterium Selenomonas ruminantium . Lactate uptake was stimulated by YEA-SACC concentrations between 2.5 and 10 g/liter, and the 5-g/liter level increased uptake 3.8-fold . When YEA-SACC concentrations were increased above the 5-g/liter level lactate uptake was decreased, but 10 g/liter still stimulated uptake more than threefold . A filter-sterilized YEA-SACC filtrate also increased lactate uptake more than fourfold at all concentrations tested (10 to 100 microliters/ml), and the 25-microliters/ml level increased uptake ninefold . Growth of S . ruminantium in medium that contained 2 g/liter of DL-lactate was stimulated more than twofold by either 2 or 5% (vol/vol) YEA-SACC filtrate after 24 h . The YEA-SACC filtrate also increased the production of acetate, propionate, total VFA, and YLACTATE (grams of cells/mole of lactate) from lactate-grown cells . Because the increase in propionate production was greater relative to acetate, a decrease in the acetate:propionate ratio was observed . Growth on lactate and uptake of radiolabeled lactate by S . ruminantium was stimulated by a filter-sterilized YEA-SACC filtrate . The concentration of L-malic acid in the YEA-SACC filtrate was 4.9 mM, and it seemed that L-malic acid played a role in the stimulation of growth on lactate as well as lactate uptake by S . ruminantium treated with YEA-SACC. Biophys J, 1991 Nov, 60(5), 1120 - 7 Mechanosensitive ion channels as reporters of bilayer expansion . A theoretical model; Markin VS et al.; Various amphipathic compounds have been found to activate mechanosensitive (MS) ion channels in the bacterium Escherichia coli . These results were interpreted qualitatively in terms of the bilayer couple hypothesis . Here we present a mathematical model that describes the results quantitatively . According to the model, the uneven partitioning of amphipaths between the monolayers of the cell membrane causes one monolayer to be compressed and the other expanded . Because the open probability (Po) of the E . coli channels increased independently of which monolayer the amphipaths partitioned into, the model suggests that Po of the MS channels is determined by the monolayer having higher tension . We derived a relation between Po and amphipath concentration . The kinetics of Po variation after exposure of the cell membrane to the amphipaths was calculated based on this relation . The results fit satisfactorily the experimental data obtained with the cationic amphipath chlorpromazine and with the anionic amphipath trinitrophenol . Experiments which should further test the predictions following from the model are discussed. Biotechnol Prog, 1991 Nov-Dec, 7(6), 495 - 500 Removal of hydrogen sulfide by Chlorobium thiosulfatophilum in immobilized-cell and sulfur-settling free-cell recycle reactors; Kim BW et al.; Bioconversion of hydrogen sulfide to elementary sulfur by the photosynthetic bacterium Chlorobium thiosulfatophilum was studied in immobilized-cell and sulfur-settling free-cell recycle reactors . The cells immobilized in strontium alginate beads excreted elementary sulfur and accumulated it as crystal in the bead matrices, which made it possible that the reactor broth remained clear and the light penetrated the reactor deeper than with the free cells . In comparison with the free cells, the immobilized cells required 30% less light energy at a H2S removal rate of 2 mM/(L.h) and showed an activity of 2.4 times that of the free cells . However, in 40 h after the reaction the deterioration of the H2S removal efficiency became significant due to the accumulation of sulfur in the beads . The scanning electron micrograph (SEM) and energy-dispersive X-ray spectrometer (EDS) studies showed that the sulfur in the beads existed within a layer of 0.4 mm from the bead surface . In the sulfur-settling free-cell recycle reactor, about 80% of the sulfur excreted by the free cells could be removed in a settler . The 4-L fed batch reactor with the settler improved the light transmission to result in a H2S removal rate of 3 mumol/(mg of protein.h), 50% higher than that without it . The settling recycle reactor was much better in the removal of H2S than the immobilized-cell reactor because the former was a continuous system with the constant removal of sulfur particles by settling and of spent medium by supplying fresh medium at the same rate as the filtering rate of the reactor broth, while the latter was essentially a batch system where toxic metabolites and produced sulfur could not be removed. Gene, 1991 Oct 30, 107(1), 171 - 2 A bacterial homolog to the mitochondrial enoyl-CoA hydratase; Beckman DL et al.; A 257-amino acid (aa) open reading frame in the photosynthetic bacterium, Rhodobacter capsulatus, shows significant homology to the mitochondrial enoyl-CoA hydratase (290 aa) . This similarity in size and sequence suggests that R . capsulatus oxidizes fatty acids using specific components, more like the mitochondrial system than the multifunctional component system of Escherichia coli. Biochem Biophys Res Commun, 1991 Oct 15, 180(1), 238 - 42 Calcium is required for the reduction of sulfite from hydrogen in a reconstituted electron transfer chain from the sulfate reducing bacterium, Desulfovibrio gigas; Chen L et al.; Calcium is found a strong stimulator of sulfite reduction from hydrogen . A coupling protein of molecular weight 65,000 can be isolated from Desulfovibrio gigas . It functions in a reconstituted electron transfer chain between hydrogenase and sulfite reductase . Its N-terminal sequence shows high homologies with calcium or magnesium binding sites from other calcium-binding proteins. J Biol Chem, 1991 Oct 5, 266(28), 18827 - 31 Adhesion of Bordetella pertussis to sulfatides and to the GalNAc beta 4Gal sequence found in glycosphingolipids; Brennan MJ et al.; The adherence of the human respiratory pathogen, Bordetella pertussis, to purified glycosphingolipids was investigated using thin layer chromatography overlay assays . Both virulent and avirulent strains of B . pertussis bound to asialo GM1 . The bacterium did not bind to the gangliosides GM1, GD1a, GD1b, and GT1b, nor to lactosylceramide, trihexosylceramide, globoside, or Forssman antigen . However, after treatment of the chromatography plates with sialidase, B . pertussis bound to the gangliosides GM1, GM2, GD1a, GD1b, and GT1b but not to GM3 . Comparison of the oligosaccharide structures of these gangliosides suggests that the minimum sugar structure needed for avid bacterial binding is GalNAc beta 4Gal . This structure has been previously implicated as a receptor for other human respiratory pathogens (Krivan, H . C., Roberts, D . D., Ginsburg, V . (1988) Proc . Natl . Acad . Sci . U.S.A 85, 6157-6161) . Virulent strains of B . pertussis also bound specifically to sulfatide . This response was dose-dependent and inhibited by the anionic polysaccharide dextran sulfate . The sulfated-sugars dextran sulfate, fucoidan, and heparin inhibited the attachment of virulent strains of B . pertussis to human WiDr cells and to hamster trachea cells indicating that sulfatides on the