Helicobacter Catalase Devoid of Catalytic Activity Protects the Bacterium against Oxidative Stress.

ABSTRACT: Catalase, a conserved and abundant enzyme found in all domains of life, dissipates the oxidant hydrogen peroxide (H₂O₂). The gastric pathogen Helicobacter pylori undergoes host-mediated oxidant stress exposure, and its catalase contains oxidizable methionine (Met) residues. We hypothesized catalase may play a large stress-combating role independent of its classical catalytic one, namely quenching harmful oxidants through its recyclable Met residues, resulting in oxidant protection to the bacterium. Two Helicobacter mutant strains (katA^H56A and katA^Y339A) containing catalase without enzyme activity but that retain all Met residues were created. These strains were much more resistant to oxidants than a catalase-deletion

SUBMITTER: Benoit SL 

PROVIDER: S-EPMC5095394 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature