title: Intermediates in the Sox sulfur oxidation pathway are bound to a sulfane conjugate of the carrier protein SoxYZ.
abstract: The Sox pathway found in many sulfur bacteria oxidizes thiosulfate to sulfate. Pathway intermediates are covalently bound to a cysteine residue in the carrier protein SoxYZ. We have used biochemical complementation by SoxYZ-conjugates to probe the identity of the intermediates in the Sox pathway. We find that unconjugated SoxYZ and SoxYZ-S-sulfonate are unlikely to be intermediates during normal turnover in disagreement with current models. By contrast, conjugates with multiple sulfane atoms are readily metabolised by the Sox pathway. The most parsimonious interpretation of these data is that the true carrier species in the Sox pathway is a SoxYZ-S-sulfane adduct.
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Grabarczyk
authors.affiliation: Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
authors.forename: Ben C
authors.initials: BC
authors.lastname: Berks
mesh_terms: D001419:Bacteria / Q000201:enzymology*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism; D010084:Oxidation-Reduction; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D015398:Signal Transduction; D013455:Sulfur / Q000378:metabolism*; D013885:Thiosulfates / Q000737:chemistry / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D013885:Thiosulfates; D013455:Sulfur; D050862:Oxidoreductases Acting on Sulfur Group Donors; D003545:Cysteine