|
|
|
|
|
|
Isolation of an Integron-Borne blaVIM-4 Type Metallo-ß-Lactamase Gene from a Carbapenem-Resistant Pseudomonas aeruginosa Clinical Isolate in Hungary. Balázs Libisch, 2004.The first integron-borne metallo-ß-lactamase gene was isolated in Hungary . The blaVIM-4 gene is located on a class 1 integron that also carries a novel blaOXA-like gene . The integron is harbored by a serotype O12 Pseudomonas aeruginosa strain and shows high structural similarity to integrons isolated in Greece and Poland . Characterization of a Fourth Tungsten-Containing Enzyme from the Hyperthermophilic Archaeon Pyrococcus furiosus. Roopali Roy, 2002.Pyrococcus furiosus grows optimally near 100°C using peptides and carbohydrates as carbon sources, and it reduces elemental sulfur (S0), if present, to H2S . Tungsten (W), an element rarely used in biology, is required for optimal growth, and three different tungsten-containing enzymes have been previously purified from this organism . They all oxidize aldehydes of various types and are thought to play primary roles in the catabolism of sugars or amino acids . Here, the purification of a fourth tungsten-containing enzyme, termed WOR 4, from cell extracts of P . furiosus grown with S0 is described . This was achieved by monitoring through multiple chromatography steps the W that is not associated with the three characterized tungstoenzymes . The N-terminal sequence of WOR 4 and the approximate molecular weight of its subunit determined electrophoretically (69,000) correspond to the product of an ORF (PF1961, wor4) present in the complete genome sequence of P . furiosus . WOR 4 is a homodimer and contains approximately one W, three Fe, three or four acid-labile sulfide, and one Ca atom per subunit . The visible and electron paramagnetic resonance spectra of the oxidized and reduced enzyme indicate the presence of an unusual iron-sulfur chromophore . WOR 4 does not oxidize aliphatic or aromatic aldehydes or hydroxy acids, nor does it reduce keto acids . Consistent with prior microarray data, the protein could not be purified from P . furiosus cells grown in the absence of S0, suggesting that it may have a role in S0 metabolism . Molecular Analysis of the Enterococcus faecalis Serotype 2 Polysaccharide Determinant. Lynn E. Hancock, 2003.We previously described a 15-kb genetic cluster consisting of 11 open reading frames (cps2A to cps2K) of Enterococcus faecalis FA2-2 that is responsible for the production of the serotype 2 capsular polysaccharide . By using transcriptional fusions to a promoterless lacZ gene, we identified two independent promoters related to the expression of the polysaccharide . Both transcription initiation sites were mapped by primer extension . Reverse transcription-PCR (RT-PCR) demonstrated the transcriptional linkage of genes present in both transcripts . Real-time RT-PCR quantification of transcripts revealed maximum transcription during log phase growth, an observation confirmed by promoter fusion studies . The heterologous expression of this pathway in Escherichia coli caused reactivity with E . faecalis type 2 antiserum, thus demonstrating the essential role of this pathway in the synthesis of the type-specific polysaccharide .
|
© 2005
Transgalactic Ltd (manufacturer of Bioscreen C software) |
Privacy Statement | P.O. Box
1393, 00101 Helsinki, Finland,
Last modified: May 25, 2005
| ||||||
