Iron release from ferrisiderophores. A multi-step mechanism involving a NADH/FMN oxidoreductase and a chemical reduction by FMNH2.
Release of iron from various ferrisiderophores (ferripyoverdines, ferrioxamines B and E, ferricrocin, ferrichrome A, ferrienterobactin and its analog ferric N,N',N''-tri(1,3,5-Tris) 2,3-dihydroxybenzoylaminomethylbenzene) was obtained through an enzymic reduction of iron, involving NADH, FMN and the ferripyoverdine reductase of Pseudomonas aeruginosa PAO1. The iron released from the same complexes was also obtained through chemical reduction of iron involving FMNH2. Evidence is given that the enzymic process acts through a FMNH2 reduction; the P. aeruginosa enzyme, purified according to its ferripyoverdine-reductase activity [Hallé, F. & Meyer, J. M., Eur. J. Biochem. 209, 613-620], functions as a NADH:FMN oxidoreductase, the FMNH2 produced being able to chemically reduce the iron complexed by siderophores. The general occurrence of such a multi-step mechanism, which denies the existence of specific ferrisiderophore reductases, is discussed.
Hallé
F
F
Laboratoire de Microbiologie, Unité de Recherche Associée au Centre National de la Recherche Scientifique, no. 1481, Université Louis Pasteur, Strasbourg, France.
Meyer
J M
JM
D038181:FMN Reductase; D005486:Flavin Mononucleotide / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D007700:Kinetics; D009243:NAD / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010084:Oxidation-Reduction; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D013379:Substrate Specificity
D009243:NAD; D005486:Flavin Mononucleotide; D007501:Iron; D038181:FMN Reductase; D009247:NADH, NADPH Oxidoreductases; C077757:ferripyoverdine reductase