Molecular and biochemical analysis of AST-1, a class A beta-lactamase from Nocardia asteroides sensu stricto.
A beta-lactamase gene was cloned from a Nocardia asteroides sensu stricto clinical isolate. A recombinant plasmid, pAST-1, expressed the beta-lactamase AST-1 in Escherichia coli JM109. Its pI was 4.8, and its relative molecular mass was 31 kDa. E. coli JM109(pAST-1) was resistant to penicillins and narrow-spectrum cephalosporins. The beta-lactamase AST-1 had a restricted hydrolytic activity spectrum. Its activity was partially inhibited by clavulanic acid but not by sulbactam and tazobactam. AST-1 is an Ambler class A beta-lactamase sharing 65% amino acid identity with beta-lactamase FAR-1, the most closely related enzyme.
Poirel
L
L
Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, Faculté de Médecine Paris-Sud, 94275 Le Kremlin-Bicêtre Cedex, France.
Laurent
F
F
Naas
T
T
Labia
R
R
Boiron
P
P
Nordmann
P
P
D000328:Adult; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D004926:Escherichia coli; D015870:Gene Expression; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009616:Nocardia asteroides / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D001618:beta-Lactamases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D011994:Recombinant Proteins; D047090:beta-Lactams; C425148:beta-lactamase AST-1; D001618:beta-Lactamases