Open AccessMolecular and Biochemical Analysis of AST-1, a Class A β-Lactamase from Nocardia asteroides Sensu Stricto
Author(s) -
Laurent Poirel,
F. Laurent,
Thierry Naas,
Roger Labia,
P. Boiron,
Patrice Nordmann
Publication year - 2001
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.45.3.878-882.2001
Subject(s) - nocardia , beta lactamase , microbiology and biotechnology , clavulanic acid , sulbactam , biology , escherichia coli , tazobactam , recombinant dna , sensu stricto , bacteria , gene , biochemistry , antibiotics , genetics , amoxicillin , antibiotic resistance , zoology , imipenem
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.