The Role of the Ω-Loop in Regulation of the Catalytic Activity of TEM-Type β-Lactamases.

ABSTRACT: Bacterial resistance to β-lactams, the most commonly used class of antibiotics, poses a global challenge. This resistance is caused by the production of bacterial enzymes that are termed β-lactamases (βLs). The evolution of serine-class A β-lactamases from penicillin-binding proteins (PBPs) is related to the formation of the Ω-loop at the entrance to the enzyme's active site. In this loop, the Glu166 residue plays a key role in the two-step catalytic cycle of hydrolysis. This residue in TEM-type β-lactamases, together with Asn170, is involved in the formation of a hydrogen bonding network with a water molecule, leading to the deacylation of the acyl-enzyme complex and the hydrolysis of the β-lactam ring of the antibiotic. The activity exhibited by the Ω-loop is attributed to the positionin

SUBMITTER: Egorov A 

PROVIDER: S-EPMC6995641 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature