Molecular Insights into Hydrogen Peroxide-sensing Mechanism of the Metalloregulator MntR in Controlling Bacterial Resistance to Oxidative Stresses.

ABSTRACT: Manganese contributes to anti-oxidative stress particularly in catalase-devoid bacteria, and DtxR family metalloregulators, through sensing cellular Mn²⁺ content, regulate its homeostasis. Here, we show that metalloregulator MntR (So-MntR) functions dually as Mn²⁺ and H₂O₂ sensors in mediating H₂O₂ resistance by an oral streptococcus. H₂O₂ disrupted So-MntR binding to Mn²⁺ transporter mntABC promoter and induced disulfide-linked dimerization of the protein. Mass spectrometry identified Cys-11/Cys-156 and Cys-11/Cys-11 disulfide-linked peptides in H₂O₂-treated So-MntR. Site mutagenesis of Cys-11 and Cys-156 and particularly Cys-11 abolished H₂O₂

SUBMITTER: Chen Z 

PROVIDER: S-EPMC5392694 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature