IUBMB Enzyme Nomenclature


Accepted name: FMN reductase (NADH)

Reaction: FMNH2 + NAD+ = FMN + NADH + H+

For diagram of reaction click here.

Other name(s): NADH-FMN reductase; NADH-dependent FMN reductase; NADH:FMN oxidoreductase; NADH:flavin oxidoreductase

Systematic name: FMNH2:NAD+ oxidoreductase

Comments: The enzyme often forms a two-component system with monooxygenases. Unlike EC, FMN reductase (NADPH), and EC, FMN reductase [NAD(P)H], this enzyme has a strong preference for NADH over NADPH, although some activity with the latter is observed [1,2]. While FMN is the preferred substrate, FAD can also be used with much lower activity [1,3].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Fontecave, M., Eliasson, R. and Reichard, P. NAD(P)H:flavin oxidoreductase of Escherichia coli. A ferric iron reductase participating in the generation of the free radical of ribonucleotide reductase. J. Biol. Chem. 262 (1987) 12325-12331. [PMID: 3305505]

2. Spyrou, G., Haggård-Ljungquist, E., Krook, M., Jörnvall, H., Nilsson, E. and Reichard, P. Characterization of the flavin reductase gene (fre) of Escherichia coli and construction of a plasmid for overproduction of the enzyme. J. Bacteriol. 173 (1991) 3673-3679. [PMID: 2050627]

3. Ingelman, M., Ramaswamy, S., Nivière, V., Fontecave, M. and Eklund, H. Crystal structure of NAD(P)H:flavin oxidoreductase from Escherichia coli. Biochemistry 38 (1999) 7040-7049. [PMID: 10353815]

[EC created 2011]

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