1h33: Difference between revisions

Reduced inorganic sulfur compounds are utilized by many bacteria as, electron donors to photosynthetic or respiratory electron transport, chains. This metabolism is a key component of the biogeochemical sulfur, cycle. The SoxAX protein is a heterodimeric c-type cytochrome involved in, thiosulfate oxidation. The crystal structures of SoxAX from the, photosynthetic bacterium Rhodovulum sulfidophilum have been solved at 1.75, A resolution in the oxidized state and at 1.5 A resolution in the, dithionite-reduced state, providing the first structural insights into the, enzymatic oxidation of thiosulfate. The SoxAX active site contains a haem, with unprecedented cysteine persulfide (cysteine sulfane) coordination., This unusual post-translational modification is also seen in, sulfurtransferases such as rhodanese. Intriguingly, this enzyme shares, further active site characteristics with SoxAX such as an adjacent, conserved arginine residue and a strongly positive electrostatic, potential. These similarities have allowed us to suggest a catalytic, mechanism for enzymatic thiosulfate oxidation. The atomic coordinates and, experimental structure factors have been deposited in the PDB with the, accession codes 1H31, 1H32 and 1H33.

1H33 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Rhodovulum_sulfidophilum Rhodovulum sulfidophilum] with HEC as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Site: HA1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1H33 OCA].  

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