3MMO

Structure of the Thioalkalivibrio nitratireducens cytochrome c nitrite reductase in complex with cyanide

Summary for 3MMO

• Entry DOI: 10.2210/pdb3mmo/pdb
• Related: 2OT4 3F29
• Descriptor: Eight-heme nitrite reductase, HEME C, CYANIDE ION, ... (9 entities in total)
• Functional Keywords: alpha protein, eight hemes c, oxidoreductase
• Biological source: Thioalkalivibrio nitratireducens
• Total number of polymer chains: 2
• Total formula weight: 133063.48

Authors

Trofimov, A.A.,Polyakov, K.M.,Boyko, K.M.,Tikhonova, T.V.,Lamzin, V.S.,Bourenkov, G.P.,Popov, V.O. (deposition date: 2010-04-20, release date: 2010-09-29, Last modification date: 2024-11-27)

Primary citation

Trofimov, A.A.,Polyakov, K.M.,Boyko, K.M.,Tikhonova, T.V.,Safonova, T.N.,Tikhonov, A.V.,Popov, A.N.,Popov, V.O.
Structures of complexes of octahaem cytochrome c nitrite reductase from Thioalkalivibrio nitratireducens with sulfite and cyanide.
Acta Crystallogr.,Sect.D, 66:1043-1047, 2010

PubMed Abstract: The structures of complexes of octahaem cytochrome c nitrite reductase from the bacterium Thioalkalivibrio nitratireducens (TvNiR) with the substrate sulfite (1.4 Å resolution; R(cryst) = 0.126) and the inhibitor cyanide (1.55 Å resolution; R(cryst) = 0.148) have been established. The complex with sulfite was prepared by the reduction of the protein crystal with sodium dithionite. The sulfite ion is bound to the iron ion of the catalytic haem through the S atom. The Fe-S distance is 2.24 Å. The structure of the cyanide complex with full occupancy of the ligand site was established for the first time for cytochrome c nitrite reductases. The cyanide ion is bound to the catalytic haem iron through the C atom. The Fe-C distance is 1.91 Å and the Fe-C-N angle is 171°. The sulfite reductase activity of TvNiR was measured at different pH values. The activity is 0.02 µmol of HS(-) per minute per milligram at pH 7.0; it decreases with increasing pH and is absent at pH 9.0.

PubMed: 20944237
DOI: 10.1107/S0907444910031665

Experimental method

X-RAY DIFFRACTION (1.55 Å)