2J7A: Crystal Structure Of Cytochrome C Nitrite Reductase Nrfha Complex From Desulfovibrio Vulgaris

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.
PDB ID: 2J7ADownload
MMDB ID: 53701
PDB Deposition Date: 2006/10/6
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 2.3  Å
Source Organism:
Similar Structures:
Biological Unit for 2J7A: hexameric; determined by author and by software (PQS)
Molecular Components in 2J7A
Label Count Molecule
Proteins (6 molecules)
Cytochrome C Nitrite Reductase Nrfa(Gene symbol: DVU0625)
Molecule annotation
Cytochrome C Quinol Dehydrogenase Nrfh(Gene symbol: DVU0624)
Molecule annotation
Chemicals (39 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB