IUBMB Enzyme Nomenclature


Accepted name: FMN reductase (NADPH)

Reaction: FMNH2 + NADP+ = FMN + NADPH + H+

For diagram of reaction click here.

Other name(s): FRP; flavin reductase P; SsuE

Systematic name: FMNH2:NADP+ oxidoreductase

Comments: The enzymes from bioluminescent bacteria contain FMN [4], while the enzyme from Escherichia coli does not [8]. The enzyme often forms a two-component system with monooxygenases such as luciferase. Unlike EC, this enzyme does not use NADH as acceptor [1,2]. While FMN is the preferred substrate, the enzyme can also use FAD and riboflavin with lower activity [3,6,8].

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


1. Gerlo, E. and Charlier, J. Identification of NADH-specific and NADPH-specific FMN reductases in Beneckea harveyi. Eur. J. Biochem. 57 (1975) 461-467. [PMID: 1175652]

2. Jablonski, E. and DeLuca, M. Purification and properties of the NADH and NADPH specific FMN oxidoreductases from Beneckea harveyi. Biochemistry 16 (1977) 2932-2936. [PMID: 880288]

3. Jablonski, E. and DeLuca, M. Studies of the control of luminescence in Beneckea harveyi: properties of the NADH and NADPH:FMN oxidoreductases. Biochemistry 17 (1978) 672-678. [PMID: 23827]

4. Lei, B., Liu, M., Huang, S. and Tu, S.C. Vibrio harveyi NADPH-flavin oxidoreductase: cloning, sequencing and overexpression of the gene and purification and characterization of the cloned enzyme. J. Bacteriol. 176 (1994) 3552-3558. [PMID: 8206832]

5. Tanner, J.J., Lei, B., Tu, S.C. and Krause, K.L. Flavin reductase P: structure of a dimeric enzyme that reduces flavin. Biochemistry 35 (1996) 13531-13539. [PMID: 8885832]

6. Liu, M., Lei, B., Ding, Q., Lee, J.C. and Tu, S.C. Vibrio harveyi NADPH:FMN oxidoreductase: preparation and characterization of the apoenzyme and monomer-dimer equilibrium. Arch. Biochem. Biophys. 337 (1997) 89-95. [PMID: 8990272]

7. Lei, B. and Tu, S.C. Mechanism of reduced flavin transfer from Vibrio harveyi NADPH-FMN oxidoreductase to luciferase. Biochemistry 37 (1998) 14623-14629. [PMID: 9772191]

8. Eichhorn, E., van der Ploeg, J.R. and Leisinger, T. Characterization of a two-component alkanesulfonate monooxygenase from Escherichia coli. J. Biol. Chem. 274 (1999) 26639-26646. [PMID: 10480865]

[EC created 2011]

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