1zv2
Cu-containing nitrite reductase
OverviewOverview
Nitrite reductase is an enzyme operating in the denitrification pathway which catalyses the conversion of nitrite (NO2(-)) to gaseous nitric oxide (NO). Here, crystal structures of the oxidized and reduced forms of the copper-containing nitrite reductase from Rhodobacter sphaeroides 2.4.3 are presented at 1.74 and 1.85 A resolution, respectively. Whereas the structure of the enzyme is very similar to those of other copper-containing nitrite reductases, folding as a trimer and containing two copper sites per monomer, the structures reported here enable conformational differences between the oxidized and reduced forms of the enzyme to be identified. In the type 1 copper site, a rotational perturbation of the side chain of the copper ligand Met182 occurs upon reduction. At the type 2 copper site, a dual conformation of the catalytic residue His287 is observed in the oxidized structure but is lacking in the reduced structure, such that the interactions of the oxidized type 2 copper ion can be regarded as adopting octahedral geometry. These findings shed light on the structural mechanism of the reduction of a copper-bound nitrite to nitric oxide and water.
About this StructureAbout this Structure
1ZV2 is a Single protein structure of sequence from Rhodobacter sphaeroides. Full crystallographic information is available from OCA.
ReferenceReference
Structures of the oxidized and reduced forms of nitrite reductase from Rhodobacter sphaeroides 2.4.3 at high pH: changes in the interactions of the type 2 copper., Jacobson F, Guo H, Olesen K, Okvist M, Neutze R, Sjolin L, Acta Crystallogr D Biol Crystallogr. 2005 Sep;61(Pt 9):1190-8. Epub 2005, Aug 16. PMID:16131751 Page seeded by OCA on Sat May 3 18:06:29 2008