Directed evolution of a beta-lactamase samples a wide variety of conformational states.

ABSTRACT: In directed evolution, enzyme activity is improved in successive generations of laboratory evolution, which can be described by a simple stepwise climb toward a peak in the fitness landscape. In a naive model of evolution, it can be assumed that each enzyme variant along this path is in a single, well-defined state that differs slightly from the previous one. We analyzed the structural changes in mutants of the β-lactamase BlaC from Mycobacterium tuberculosis obtained via directed evolution for increased ceftazidime hydrolysis activity. Crystal structures of three successive mutants only show an increase in the dynamics of a loop that lines the active site (Ω-loop), enabling better access of the large substrate. However, NMR spectra of wild type and nine mutants of different branches of th

SUBMITTER: Sun J 

PROVIDER: S-EPMC12514840 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature