title: The redox-sensing regulator YodB senses quinones and diamide via a thiol-disulfide switch in Bacillus subtilis.
abstract: The MarR/DUF24-type repressor YodB controls the azoreductase AzoR1, the nitroreductase YodC and the redox-sensing regulator Spx in response to quinones and diamide in Bacillus subtilis. Previously, we showed using a yodBCys6-Ala mutant that the conserved Cys6 apparently contributes to the DNA-binding activity of YodB in vivo. Here, we present data that mutation of Cys6 to Ser led to a form of the protein that was reduced in redox-sensing in response to diamide and 2-methylhydroquinone (MHQ) in vivo. DNA-binding experiments indicate that YodB is regulated by a reversible thiol-modification in response to diamide and MHQ in vitro. Redox-regulation of YodB involves Cys6-Cys101' intermolecular disulfide formation by diamide and quinones in vitro. Diagonal Western blot analyses confirm the formation of intersubunit disulfides in YodB in vivo that require the conserved Cys6 and either of the C-terminal Cys101' or Cys108' residues. This study reveals a thiol-disulfide switch model of redox-regulation for the YodB repressor to sense electrophilic compounds in vivo.
authors.affiliation: Institute for Microbiology, Ernst-Moritz-Arndt-University of Greifswald, Greifswald, Germany.
authors.forename: Bui Khanh
authors.initials: BK
authors.lastname: Chi
authors.forename: Dirk
authors.initials: D
authors.lastname: Albrecht
authors.forename: Katrin
authors.initials: K
authors.lastname: Gronau
authors.forename: Dörte
authors.initials: D
authors.lastname: Becher
authors.forename: Michael
authors.initials: M
authors.lastname: Hecker
authors.forename: Haike
authors.initials: H
authors.lastname: Antelmann
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D003545:Cysteine / Q000378:metabolism; D003958:Diamide / Q000378:metabolism*; D004220:Disulfides / Q000378:metabolism*; D008958:Models, Molecular; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D009154:Mutation; D010084:Oxidation-Reduction; D011809:Quinones / Q000378:metabolism*; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015203:Reproducibility of Results; D016415:Sequence Alignment; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004220:Disulfides; D011809:Quinones; D012097:Repressor Proteins; D013438:Sulfhydryl Compounds; D003958:Diamide; D003545:Cysteine