Structural insights into alterations in the substrate spectrum of serine-β-lactamase OXA-10 from Pseudomonas aeruginosa by single amino acid substitutions.

ABSTRACT: The extensive use of β-lactam antibiotics has led to significant resistance, primarily due to hydrolysis by β-lactamases. OXA class D β-lactamases can hydrolyze a wide range of β-lactam antibiotics, rendering many treatments ineffective. We investigated the effects of single amino acid substitutions in OXA-10 on its substrate spectrum. Broad-spectrum variants with point mutations were searched and biochemically verified. Three key residues, G157D, A124T, and N73S, were confirmed in the variants, and their crystal structures were determined. Based on an enzyme kinetics study, the hydrolytic activity against broad-spectrum cephalosporins, particularly ceftazidime, was significantly enhanced by the G157D mutation in loop 2. The A124T or N73S mutation close to loop 2 also resulted in higher ce

SUBMITTER: Lee CE 

PROVIDER: S-EPMC11497580 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature