Molecular and biochemical analysis of AST-1, a class A beta-lactamase from Nocardia asteroides sensu stricto

Antimicrob Agents Chemother. 2001 Mar;45(3):878-82. doi: 10.1128/AAC.45.3.878-882.2001.

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

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Anti-Bacterial Agents / metabolism
  • Anti-Bacterial Agents / pharmacology
  • Escherichia coli
  • Gene Expression
  • Humans
  • Male
  • Microbial Sensitivity Tests
  • Molecular Sequence Data
  • Nocardia asteroides / drug effects
  • Nocardia asteroides / enzymology*
  • Nocardia asteroides / genetics
  • Nocardia asteroides / metabolism
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • beta-Lactamases / genetics
  • beta-Lactamases / isolation & purification
  • beta-Lactamases / metabolism*
  • beta-Lactams

Substances

  • Anti-Bacterial Agents
  • Recombinant Proteins
  • beta-Lactams
  • beta-lactamase AST-1
  • beta-Lactamases