Structure of the Thioalkalivibrio nitratireducens cytochrome c nitrite reductase reduced by sodium dithionite (sulfite complex)Structure of the Thioalkalivibrio nitratireducens cytochrome c nitrite reductase reduced by sodium dithionite (sulfite complex)

Structural highlights

3fo3 is a 2 chain structure with sequence from Thioalkalivibrio nitratireducens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.4Å
Ligands:, , , , , , , , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NIR_THIND Catalyzes the reduction of nitrite to ammonia, consuming six electrons in the process (PubMed:16500161, PubMed:22281743). Has very low activity toward hydroxylamine (PubMed:16500161). Has even lower activity toward sulfite (PubMed:16500161, PubMed:22281743). Sulfite reductase activity is maximal at neutral pH (PubMed:20944237).[1] [2] [3]

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The structures of complexes of octahaem cytochrome c nitrite reductase from the bacterium Thioalkalivibrio nitratireducens (TvNiR) with the substrate sulfite (1.4 A resolution; R(cryst) = 0.126) and the inhibitor cyanide (1.55 A 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 A. 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 A and the Fe-C-N angle is 171 degrees . The sulfite reductase activity of TvNiR was measured at different pH values. The activity is 0.02 micromol of HS(-) per minute per milligram at pH 7.0; it decreases with increasing pH and is absent at pH 9.0.

Structures of complexes of octahaem cytochrome c nitrite reductase from Thioalkalivibrio nitratireducens with sulfite and cyanide.,Trofimov AA, Polyakov KM, Boyko KM, Tikhonova TV, Safonova TN, Tikhonov AV, Popov AN, Popov VO Acta Crystallogr D Biol Crystallogr. 2010 Oct;66(Pt 10):1043-7. Epub 2010, Sep 18. PMID:20944237[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Tikhonova TV, Slutsky A, Antipov AN, Boyko KM, Polyakov KM, Sorokin DY, Zvyagilskaya RA, Popov VO. Molecular and catalytic properties of a novel cytochrome c nitrite reductase from nitrate-reducing haloalkaliphilic sulfur-oxidizing bacterium Thioalkalivibrio nitratireducens. Biochim Biophys Acta. 2006 Apr;1764(4):715-23. Epub 2006 Feb 9. PMID:16500161 doi:http://dx.doi.org/10.1016/j.bbapap.2005.12.021
  2. Trofimov AA, Polyakov KM, Boyko KM, Tikhonova TV, Safonova TN, Tikhonov AV, Popov AN, Popov VO. Structures of complexes of octahaem cytochrome c nitrite reductase from Thioalkalivibrio nitratireducens with sulfite and cyanide. Acta Crystallogr D Biol Crystallogr. 2010 Oct;66(Pt 10):1043-7. Epub 2010, Sep 18. PMID:20944237 doi:10.1107/S0907444910031665
  3. Trofimov AA, Polyakov KM, Tikhonova TV, Tikhonov AV, Safonova TN, Boyko KM, Dorovatovskii PV, Popov VO. Covalent modifications of the catalytic tyrosine in octahaem cytochrome c nitrite reductase and their effect on the enzyme activity. Acta Crystallogr D Biol Crystallogr. 2012 Feb;68(Pt 2):144-53. Epub 2012, Jan 13. PMID:22281743 doi:10.1107/S0907444911052632
  4. Trofimov AA, Polyakov KM, Boyko KM, Tikhonova TV, Safonova TN, Tikhonov AV, Popov AN, Popov VO. Structures of complexes of octahaem cytochrome c nitrite reductase from Thioalkalivibrio nitratireducens with sulfite and cyanide. Acta Crystallogr D Biol Crystallogr. 2010 Oct;66(Pt 10):1043-7. Epub 2010, Sep 18. PMID:20944237 doi:10.1107/S0907444910031665

3fo3, resolution 1.40Å

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