2j7a
Crystal structure of cytochrome c nitrite reductase NrfHA complex from Desulfovibrio vulgaris
Structural highlights
FunctionNRFA_NITV2 Catalytic subunit of the cytochrome c nitrite reductase holocomplex NrfHA (PubMed:11004582, PubMed:17139260, PubMed:18597779, PubMed:25534748). Has both nitrite and sulfite reductase activities (PubMed:11004582). Catalyzes the reduction of nitrite to ammonia, consuming six electrons acquired by the electron donor subunit NrfH from the menaquinone pool, in an anaerobic respiratory process of nitrite (PubMed:11004582, PubMed:17139260, PubMed:18597779, PubMed:25534748). The other biological function of the NrfHA holocomplex is to detoxify nitrite (PubMed:15547266, PubMed:25534748). This function is essential for the survival of this organism as it enables it to overcome inhibition by nitrite, which is produced by other organisms living in the same environment (Probable).[1] [2] [3] [4] [5] 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 PubMedOxidation of membrane-bound quinol molecules is a central step in the respiratory electron transport chains used by biological cells to generate ATP by oxidative phosphorylation. A novel family of cytochrome c quinol dehydrogenases that play an important role in bacterial respiratory chains was recognised in recent years. Here, we describe the first structure of a cytochrome from this family, NrfH from Desulfovibrio vulgaris, which forms a stable complex with its electron partner, the cytochrome c nitrite reductase NrfA. One NrfH molecule interacts with one NrfA dimer in an asymmetrical manner, forming a large membrane-bound complex with an overall alpha(4)beta(2) quaternary arrangement. The menaquinol-interacting NrfH haem is pentacoordinated, bound by a methionine from the CXXCHXM sequence, with an aspartate residue occupying the distal position. The NrfH haem that transfers electrons to NrfA has a lysine residue from the closest NrfA molecule as distal ligand. A likely menaquinol binding site, containing several conserved and essential residues, is identified. X-ray structure of the membrane-bound cytochrome c quinol dehydrogenase NrfH reveals novel haem coordination.,Rodrigues ML, Oliveira TF, Pereira IA, Archer M EMBO J. 2006 Dec 13;25(24):5951-60. Epub 2006 Nov 30. PMID:17139260[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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