A Suicide Mutation Affecting Proton Transfers to High-Valent Hemes Causes Inactivation of MauG during Catalysis.

ABSTRACT: In the absence of its substrate, the autoreduction of the high-valent bis-Fe^IV state of the hemes of MauG to the diferric state proceeds via a Compound I-like and then a Compound II-like intermediate. This process is coupled to oxidative damage to specific methionine residues and inactivation of MauG. The autoreduction of a P107V MauG variant, which is more prone to oxidative damage, proceeds directly from the bis-Fe^IV to the Compound II-like state with no detectable Compound I intermediate. Comparison of the crystal structures of native and P107V MauG reveals that this mutation alters the positions of amino acid residues in the heme site as well as the water network that delivers protons from the solvent to the hemes during their reduction. Kinetic, spectroscopic, an

SUBMITTER: Ma Z 

PROVIDER: S-EPMC5339880 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature