title: Redox states of Desulfovibrio vulgaris DsrC, a key protein in dissimilatory sulfite reduction.
abstract: Dissimilatory reduction of sulfite is carried out by the siroheme enzyme DsrAB, with the involvement of the protein DsrC, which has two conserved redox-active cysteines. DsrC was initially believed to be a third subunit of DsrAB. Here, we report a study of the distribution of DsrC in cell extracts to show that, in the model sulfate reducer Desulfovibrio vulgaris, the majority of DsrC is not associated with DsrAB and is thus free to interact with other proteins. In addition, we developed a cysteine-labelling gel-shift assay to monitor the DsrC redox state and behaviour, and procedures to produce the different redox forms. The oxidized state of DsrC with an intramolecular disulfide bond, which is proposed to be a key metabolic intermediate, could be successfully produced for the first time by treatment with arginine.
authors.affiliation: Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: Sofia S
authors.initials: SS
authors.lastname: Venceslau
authors.forename: John R
authors.initials: JR
authors.lastname: Cort
authors.forename: Erin S
authors.initials: ES
authors.lastname: Baker
authors.forename: Rosalie K
authors.initials: RK
authors.lastname: Chu
authors.forename: Errol W
authors.initials: EW
authors.lastname: Robinson
authors.forename: Christiane
authors.initials: C
authors.lastname: Dahl
authors.forename: Lígia M
authors.initials: LM
authors.lastname: Saraiva
authors.forename: Inês A C
authors.initials: IA
authors.lastname: Pereira
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D016969:Desulfovibrio vulgaris / Q000201:enzymology*; D010084:Oxidation-Reduction; D050864:Sulfite Reductase (NADPH) / Q000737:chemistry / Q000378:metabolism*; D013447:Sulfites / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D013447:Sulfites; D050864:Sulfite Reductase (NADPH)
keywords: Desulfovibrio; Dissimilatory sulfite reductase; DsrC; Gel-shift assay; MalPEG