1NDR

CRYSTALLOGRAPHIC STRUCTURE OF A BLUE COPPER NITRITE REDUCTASE FROM ALCALIGENES XYLOSOXIDANS

Summary for 1NDR

• Entry DOI: 10.2210/pdb1ndr/pdb
• Descriptor: NITRITE REDUCTASE, COPPER (II) ION (3 entities in total)
• Functional Keywords: blue copper nitrite reductase, copper protein, nitrite reduction, reductase
• Biological source: Achromobacter xylosoxidans
• Cellular location: Periplasm (By similarity): P81445
• Total number of polymer chains: 3
• Total formula weight: 103706.41

Authors

Dodd, F.E.,Hasnain, S.S.,Abraham, Z.H.L.,Eady, R.R.,Smith, B.E. (deposition date: 1997-01-23, release date: 1997-07-07, Last modification date: 2024-05-22)

Primary citation

Dodd, F.E.,Hasnain, S.S.,Abraham, Z.H.,Eady, R.R.,Smith, B.E.
Structures of a blue-copper nitrite reductase and its substrate-bound complex.
Acta Crystallogr.,Sect.D, 53:406-418, 1997

PubMed Abstract: Copper-containing nitrite reductases (NiR's) have been conveniently subdivided into blue and green NiR's which are thought to be redox partners of azurins and pseudo-azurins, respectively. Crystal structures of two green NiR's have recently been determined. Alcaligenes xylosoxidans has been shown to have a blue-copper nitrite reductase (AxNiR) and two azurins with 67% homology both of which donate electrons to it effectively. The first crystal structure of a blue NiR (AxNiR) in its oxidized and nitrite-bound forms, with particular emphasis to the Cu sites, is presented. The Cu-Smet distance is the same as those in the green NiR's. Thus, the length of this interaction is unlikely to be responsible for differences in colour. Crystallographic data presented here taken together with structural data of other single Cu type-1 proteins and their mutants suggest that the displacement of Cu from the strong ligand plane is perhaps the cause for the differences in colour observed for otherwise 'classical' blue Cu centre. Nitrite is observed binding to the catalytic Cu in a bidentate fashion displacing the water molecule, offering a neat rationalization for the XAFS observation that the type-2 Cu-ligand distances increase on nitrite binding as a result of increased coordination. These results are discussed in terms of enzyme mechanism.

PubMed: 15299906
DOI: 10.1107/S0907444997002667

Experimental method

X-RAY DIFFRACTION (3 Å)