Structural highlights
Function
[NORV_ECOLI] Anaerobic nitric oxide reductase; uses NADH to detoxify nitric oxide (NO), protecting several 4Fe-4S NO-sensitive enzymes. Has at least 2 reductase partners, only one of which (NorW, flavorubredoxin reductase) has been identified. NO probably binds to the di-iron center; electrons enter from the reductase at rubredoxin and are transferred sequentially to the FMN center and the di-iron center. Also able to function as an aerobic oxygen reductase.[1] [2]
Publication Abstract from PubMed
Flavodiiron proteins (FDPs) are a family of enzymes endowed with bona fide oxygen- and/or nitric oxide-reductase activity, although their substrate specificity determinants remain elusive. After a comprehensive comparison of available three-dimensional structures, particularly of FDPs with a clear preference towards either O2 or NO, two main differences were identified near the diiron active site, which led to the construction of site-directed mutants of Y271 and K53 in the oxygen reducing Entamoeba histolytica EhFdp1. The biochemical and biophysical properties of these mutants were studied by UV-visible and electron paramagnetic resonance (EPR) spectroscopies coupled to potentiometry. Their reactivity with O2 and NO was analyzed by stopped-flow absorption spectroscopy and amperometric methods. These mutations, while keeping the overall properties of the redox cofactors, resulted in increased NO reductase activity and faster inactivation of the enzyme in the reaction with O2, pointing to a role of the mutated residues in substrate selectivity.
Flavodiiron oxygen reductase from Entamoeba histolytica: Modulation of substrate preference by tyrosine 271 and lysine 53.,Goncalves VL, Vicente JB, Pinto L, Romao CV, Frazao C, Sarti P, Giuffre A, Teixeira M J Biol Chem. 2014 Aug 23. pii: jbc.M114.579086. PMID:25151360[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Gardner AM, Helmick RA, Gardner PR. Flavorubredoxin, an inducible catalyst for nitric oxide reduction and detoxification in Escherichia coli. J Biol Chem. 2002 Mar 8;277(10):8172-7. Epub 2001 Dec 18. PMID:11751865 doi:http://dx.doi.org/10.1074/jbc.M110471200
- ↑ Gomes CM, Giuffre A, Forte E, Vicente JB, Saraiva LM, Brunori M, Teixeira M. A novel type of nitric-oxide reductase. Escherichia coli flavorubredoxin. J Biol Chem. 2002 Jul 12;277(28):25273-6. Epub 2002 May 6. PMID:12101220 doi:http://dx.doi.org/10.1074/jbc.M203886200
- ↑ Goncalves VL, Vicente JB, Pinto L, Romao CV, Frazao C, Sarti P, Giuffre A, Teixeira M. Flavodiiron oxygen reductase from Entamoeba histolytica: Modulation of substrate preference by tyrosine 271 and lysine 53. J Biol Chem. 2014 Aug 23. pii: jbc.M114.579086. PMID:25151360 doi:http://dx.doi.org/10.1074/jbc.M114.579086
