2j7a: Difference between revisions

Oxidation 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.

2J7A is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Desulfovibrio_vulgaris Desulfovibrio vulgaris] with CA, ACT, HEM and LMT as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2J7A OCA].  

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