CONTRIBUTION OF MUTANT ANALYSIS TO THE UNDERSTANDING OF ENZYME CATALYSIS - THE CASE OF CLASS-A BETA-LACTAMASES

Class A beta-lactamases represent a family of well studied enzymes. Th ey are responsible for many antibiotic resistance phenomena and thus f or numerous failures in clinical chemotherapy. Despite the facts that five structures are known at high resolution and that detailed analyse s of enzymes modified by site-directed mutagenesis have been performed , their exact catalytic mechanism remains controversial. This review a ttempts to summarize and to discuss the many available data.