Identification of altered function alleles that affect Bacillus subtilis PerR metal ion selectivity.

ABSTRACT: Bacillus subtilis PerR is a Fur family repressor that senses hydrogen peroxide by metal-catalyzed oxidation. PerR contains a structural Zn(II) ion (Site 1) and a regulatory metal binding site (Site 2) that, upon association with either Mn(II) or Fe(II), allosterically activates DNA binding. In addition, a third less conserved metal binding site (Site 3) is present near the dimer interface in several crystal structures of homologous Fur family proteins. Here, we show that PerR proteins with substitutions of putative Site 3 residues (Y92A, E114A and H128A) are functional as repressors, but are unexpectedly compromised in their ability to sense H(2)O(2). Consistently, these mutants utilize Mn(II) but not Fe(II) as a co-repressor in vivo. Metal titrations failed to identify a third binding sit

SUBMITTER: Ma Z 

PROVIDER: S-EPMC3130269 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature