title: Sulfur oxidation in Paracoccus pantotrophus: interaction of the sulfur-binding protein SoxYZ with the dimanganese SoxB protein.
abstract: The central protein of the sulfur-oxidizing enzyme system of Paracoccus pantotrophus, SoxYZ, formed complexes with subunits associated and covalently bound. In denaturing SDS-polyacrylamide gel electrophoresis (PAGE) SoxY migrated at 12 and SoxZ at 16kDa. SDS-PAGE of homogeneous SoxYZ without reductant separated dimeric complexes of 25, 29, and 32kDa identified by the N-terminal amino acid sequences as SoxY-Y, SoxY-Z, and SoxZ-Z, and subunit cleavage by reduction suggested their linkage via protein disulfide bonds. SoxYZ was reversibly redox active between -0.25 and 0.2V, as monitored by a combined electrochemical and FTIR spectroscopic approach. The dimanganese SoxB protein (58.611Da) converted the covalently linked heterodimer SoxY-Z to SoxYZ with associated subunits which in turn aggregated to the heterotetramer Sox(YZ)(2). This reaction depended on time and the SoxB concentration, and demonstrated the interaction of these two Sox proteins.
authors.affiliation: Lehrstuhl für Technische Mikrobiologie, Fachbereich Chemietechnik, Universität Dortmund, Emil-Figge-Strasse 66, D44221, Dortmund, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Quentmeier
authors.forename: Petra
authors.initials: P
authors.lastname: Hellwig
authors.forename: Frank
authors.initials: F
authors.lastname: Bardischewsky
authors.forename: Gerlinde
authors.initials: G
authors.lastname: Grelle
authors.forename: Regine
authors.initials: R
authors.lastname: Kraft
authors.forename: Cornelius G
authors.initials: CG
authors.lastname: Friedrich
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry*; D019281:Dimerization; D004789:Enzyme Activation; D046911:Macromolecular Substances; D008667:Metalloproteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D042084:Paracoccus pantotrophus / Q000737:chemistry*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D013455:Sulfur / Q000737:chemistry*
chemical_list: D002352:Carrier Proteins; D046911:Macromolecular Substances; D008667:Metalloproteins; D021122:Protein Subunits; D013455:Sulfur