2c1d
From Proteopedia
CRYSTAL STRUCTURE OF SOXXA FROM P. PANTOTROPHUS
Structural highlights
Function[SOXA_PARPN] C-type diheme cytochrome, which is part of the SoxAX cytochrome complex involved in sulfur oxidation. The SoxAX complex catalyzes the formation of a heterodisulfide bond between the conserved cysteine residue on a sulfur carrier SoxYZ complex subunit SoxY and thiosulfate or other inorganic sulfur substrates. This leads to the liberation of two electrons, which may be transferred from the SoxAX complex to another cytochrome c that then channels them into the respiratory electron transport chain. Some electrons may be used for reductive CO(2) fixation.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe sulfur-oxidizing enzyme system (Sox) of the chemotroph Paracoccus pantotrophus is composed of several proteins, which together oxidize hydrogen sulfide, sulfur, thiosulfate or sulfite and transfers the gained electrons to the respiratory chain. The hetero-dimeric cytochrome c complex SoxXA functions as heme enzyme and links covalently the sulfur substrate to the thiol of the cysteine-138 residue of the SoxY protein of the SoxYZ complex. Here, we report the crystal structure of the c-type cytochrome complex SoxXA. The structure could be solved by molecular replacement and refined to a resolution of 1.9A identifying the axial heme-iron coordination involving an unusual Cys-251 thiolate of heme2. Distance measurements between the three heme groups provide deeper insight into the electron transport inside SoxXA and merge in a better understanding of the initial step of the aerobic sulfur oxidation process in chemotrophic bacteria. Structure of the cytochrome complex SoxXA of Paracoccus pantotrophus, a heme enzyme initiating chemotrophic sulfur oxidation.,Dambe T, Quentmeier A, Rother D, Friedrich C, Scheidig AJ J Struct Biol. 2005 Dec;152(3):229-34. Epub 2005 Nov 2. PMID:16297640[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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