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The Bacillus subtilis yqjI Gene Encodes the NADP+-Dependent 6-P-Gluconate Dehydrogenase in the Pentose Phosphate Pathway. Nicola Zamboni, 2004.Despite the importance of the oxidative pentose phosphate (PP) pathway as a major source of reducing power and metabolic intermediates for biosynthetic processes, almost no direct genetic or biochemical evidence is available for Bacillus subtilis . Using a combination of knockout mutations in known and putative genes of the oxidative PP pathway and 13C-labeling experiments, we demonstrated that yqjI encodes the NADP+-dependent 6-P-gluconate dehydrogenase, as was hypothesized previously from sequence similarities . Moreover, YqjI was the predominant isoenzyme during glucose and gluconate catabolism, and its role in the oxidative PP pathway could not be played by either of two homologues, GntZ and YqeC . This conclusion is in contrast to the generally held view that GntZ is the relevant isoform; hence, we propose a new designation for yqjI, gndA, the monocistronic gene encoding the principal 6-P-gluconate dehydrogenase . Although we demonstrated the NAD+-dependent 6-P-gluconate dehydrogenase activity of GntZ, gntZ mutants exhibited no detectable phenotype on glucose, and GntZ did not contribute to PP pathway fluxes during growth on glucose . Since gntZ mutants grew normally on gluconate, the functional role of GntZ remains obscure, as does the role of the third homologue, YqeC . Knockout of the glucose-6-P dehydrogenase-encoding zwf gene was primarily compensated for by increased glycolytic fluxes, but about 5% of the catabolic flux was rerouted through the gluconate bypass with glucose dehydrogenase as the key enzyme . Antibiotic-Inducible Promoter Regulated by the Cell Envelope Stress-Sensing Two-Component System LiaRS of Bacillus subtilis. Thorsten Mascher, 2004.Soil bacteria are among the most prodigious producers of antibiotics . The Bacillus subtilis LiaRS (formerly YvqCE) two-component system is one of several antibiotic-sensing systems that coordinate the genetic response to cell wall-active antibiotics . Upon the addition of vancomycin or bacitracin, LiaRS autoregulates the liaIHGFSR operon . We have characterized the promoter of the lia operon and defined the cis-acting sequences necessary for antibiotic-inducible gene expression . A survey for compounds that act as inducers of the lia promoter revealed that it responds strongly to a subset of cell wall-active antibiotics that interfere with the lipid II cycle in the cytoplasmic membrane (bacitracin, nisin, ramoplanin, and vancomycin) . Chemicals that perturb the cytoplasmic membrane, such as organic solvents, are also weak inducers . Thus, the reporter derived from PliaI (the liaI promoter) provides a tool for the detection and classification of antimicrobial compounds . Immobilization of Saccharomyces cerevisiae Cystathionine  -Lyase and Application of the Product to Cystathionine Synthesis.Shuzo Yamagata, 2004.Cystathionine -lyase of Saccharomyces cerevisiae was immobilized to aminohexyl-Sepharose through the cofactor pyridoxal 5'-phosphate and was characterized with respect to its cystathionine
-synthase activity . The immobilized product was so stable that it repeatedly catalyzed as many as five cycles of the reaction without losing activity .
Roles of PucR, GlnR, and TnrA in Regulating Expression of the Bacillus subtilis ure P3 Promoter. Jaclyn L. Brandenburg, 2002.Expression of the P3 promoter of the Bacillus subtilis ureABC operon is activated during nitrogen-limited growth by PucR, the transcriptional regulator of the purine-degradative genes . Addition of allantoic acid, a purine-degradative intermediate, to nitrogen-limited cells stimulated transcription of ure P3 twofold . Since urea is produced during purine degradation in B . subtilis, regulation of ureABC expression by PucR allows purines to be completely degraded to ammonia . The nitrogen transcription factor TnrA was found to indirectly regulate ure P3 expression by activating pucR expression . The two consensus GlnR/TnrA binding sites located in the ure P3 promoter region were shown to be required for negative regulation by GlnR . Mutational analysis indicates that a cooperative interaction occurs between GlnR dimers bound at these two sites . B . subtilis is the first example where urease expression is both nitrogen regulated and coordinately regulated with the enzymes involved in purine transport and degradation . Host Range of Chlamydiaphages  CPAR39 and Chp3.J. S. Everson, 2003.The host range of CPAR39 is limited to four Chlamydophila species: C . abortus, C . caviae, C . pecorum, and C . pneumoniae . Chp3 (a newly discovered bacteriophage isolated from C . pecorum) shares three of these hosts (C . abortus, C . caviae, and C . pecorum) but can additionally infect Chlamydophila felis . The ability to support replication was directly correlated with the binding properties of the respective bacteriophages with their host species . Binding studies also show that
CPAR39 and Chp3 use different host receptors to infect the same host cells: cell binding is sensitive to proteinase K treatment, confirming that the chlamydiaphage receptors are proteinaceous in nature .
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