1nds: Difference between revisions

Revision as of 15:05, 21 February 2008

CRYSTALLOGRAPHIC STRUCTURE OF A SUBSTRATE BOUND BLUE COPPER NITRITE REDUCTASE FROM ALCALIGENES XYLOSOXIDANS

OverviewOverview

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.

About this StructureAbout this Structure

1NDS is a Single protein structure of sequence from Achromobacter xylosoxidans with and as ligands. Active as Transferred entry: 1.7.2.1, with EC number 1.7.99.3 Known structural/functional Sites: , , , , and . Full crystallographic information is available from OCA.

ReferenceReference

Structures of a blue-copper nitrite reductase and its substrate-bound complex., Dodd FE, Hasnain SS, Abraham ZH, Eady RR, Smith BE, Acta Crystallogr D Biol Crystallogr. 1997 Jul 1;53(Pt 4):406-18. PMID:15299906

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 ==Overview==
-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.
+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.
 ==About this Structure==
@@ Line 13: / Line 13: @@
 [[Category: Achromobacter xylosoxidans]]
 [[Category: Single protein]]
-[[Category: Transferred entry: 1.7.2.1]]
+[[Category: Transferred entry: 1 7.2 1]]
-[[Category: Abraham, Z.H.L.]]
+[[Category: Abraham, Z H.L.]]
-[[Category: Dodd, F.E.]]
+[[Category: Dodd, F E.]]
-[[Category: Eady, R.R.]]
+[[Category: Eady, R R.]]
-[[Category: Hasnain, S.S.]]
+[[Category: Hasnain, S S.]]
-[[Category: Smith, B.E.]]
+[[Category: Smith, B E.]]
 [[Category: CU]]
 [[Category: NO2]]
@@ Line 26: / Line 26: @@
 [[Category: reductase]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb  3 09:53:50 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:05:02 2008''