Abstract
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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adult
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Amino Acid Sequence
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Anti-Bacterial Agents / metabolism
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Anti-Bacterial Agents / pharmacology
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Escherichia coli
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Gene Expression
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Humans
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Male
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Microbial Sensitivity Tests
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Molecular Sequence Data
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Nocardia asteroides / drug effects
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Nocardia asteroides / enzymology*
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Nocardia asteroides / genetics
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Nocardia asteroides / metabolism
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Recombinant Proteins / isolation & purification
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Recombinant Proteins / metabolism
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Sequence Homology, Amino Acid
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beta-Lactamases / genetics
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beta-Lactamases / isolation & purification
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beta-Lactamases / metabolism*
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beta-Lactams
Substances
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Anti-Bacterial Agents
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Recombinant Proteins
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beta-Lactams
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beta-lactamase AST-1
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beta-Lactamases