MetaCyc Compound: FMN

Synonyms: flavin mononucleotide, riboflavin 5'-phosphate

Superclasses: an acceptora redox electron carrier
an organic heterocyclic compoundan organic heterobicyclic compounda pteridinea benzopteridinea flavinan oxidized flavin
an organic heterocyclic compoundan organonitrogen heterocyclic compounda pteridinea benzopteridinea flavinan oxidized flavin

FMN is the principal form in which riboflavin (vitamin B2) is found in cells and tissues. While it takes more energy to produce than the non-phosphorylated form of riboflavin, it is more soluble.

FMN is produced from riboflavin by the enzyme riboflavin kinase, and functions as prosthetic group of various oxidoreductases including NADH dehydrogenase. During the catalytic cycle, FMN cycles between the oxidized (FMN), semiquinone (FMNH) and reduced ( FMNH2) forms, enabling it to take part in both one and two electron transfers. FMN is a stronger oxidizing agent than NAD.

Chemical Formula: C17H18N4O9P

Molecular Weight: 453.32 Daltons

Monoisotopic Molecular Weight: 456.10461480379996 Daltons

FMN compound structure

SMILES: CC2(=CC1(N=C3(C(=O)[N-]C(=O)N=C(N(CC(O)C(O)C(O)COP([O-])(=O)[O-])C=1C=C(C)2)3)))

InChI: InChI=1S/C17H21N4O9P/c1-7-3-9-10(4-8(7)2)21(15-13(18-9)16(25)20-17(26)19-15)5-11(22)14(24)12(23)6-30-31(27,28)29/h3-4,11-12,14,22-24H,5-6H2,1-2H3,(H3,20,25,26,27,28,29)/p-3/t11-,12+,14-/m0/s1


Unification Links: CAS:146-17-8, ChEBI:58210, HMDB:HMDB01520, IAF1260:33703, KEGG:C00061, MetaboLights:MTBLC58210, PubChem:44229199, Wikipedia:Flavin_mononucleotide

Standard Gibbs Free Energy of Change Formation (ΔfG in kcal/mol): -207.15736Inferred by computational analysis [Latendresse13]

Reactions known to consume the compound:

5,6-dimethylbenzimidazole biosynthesis I (aerobic) :
FMNH2 + NAD(P)+FMN + NAD(P)H + 2 H+

actinorhodin biosynthesis :
actinorhodin intermediate + NADH + FMN + 2 H+ + oxygen → actinorhodin + NAD+ + FMNH2

bacterial bioluminescence :
NADP+ + FMNH2 ← NADPH + FMN + 2 H+
NAD+ + FMNH2 ← NADH + FMN + 2 H+
FMNH2 + NAD(P)+FMN + NAD(P)H + 2 H+

flavin biosynthesis I (bacteria and plants) , flavin biosynthesis II (archaea) , flavin biosynthesis III (fungi) , flavin biosynthesis IV (mammalian) :
ATP + FMN + H+ → FAD + diphosphate

two-component alkanesulfonate monooxygenase :
NADP+ + FMNH2 ← NADPH + FMN + 2 H+

Not in pathways:
FMN + H2O → riboflavin + phosphate

Reactions known to produce the compound:

5,6-dimethylbenzimidazole biosynthesis I (aerobic) , flavin biosynthesis I (bacteria and plants) , flavin biosynthesis III (fungi) , flavin biosynthesis IV (mammalian) :
riboflavin + ATP → ADP + FMN + H+

adenosylcobalamin biosynthesis from cobyrinate a,c-diamide I , adenosylcobalamin biosynthesis from cobyrinate a,c-diamide II :
2 cob(I)yrinate a,c-diamide + FMN + 3 H+ ← 2 cob(II)yrinate a,c-diamide + FMNH2

androstenedione degradation :
3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione + FMNH2 + oxygen → 3,4-dihydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione + FMN + H+ + H2O

bacterial bioluminescence :
a long-chain aldehyde + FMNH2 + oxygen → a long-chain fatty acid + hν + FMN + H2O + 2 H+

butirosin biosynthesis :
a 4-(γ-L-glutamylamino)butanoyl-[BtrI acyl-carrier protein] + FMNH2 + oxygen → a 4-(γ-L-glutamylamino)-(S)-2-hydroxy-butanoyl-[BtrI acyl-carrier protein] + FMN + H2O + H+

dibenzothiophene desulfurization :
dibenzothiophene-5,5-dioxide + 2 FMNH2 + oxygen → 2'-hydroxybiphenyl-2-sulfinate + 2 FMN + H2O + 3 H+

dimethyl sulfide degradation II (oxidation) :
dimethyl sulfone + 2 FMNH2 + 2 oxygen → methanesulfonate + formaldehyde + 2 FMN + 2 H2O + 3 H+

flavin biosynthesis II (archaea) :
riboflavin + CTP → CDP + FMN + H+

nitrilotriacetate degradation :
nitrilotriacetate + FMNH2 + oxygen → iminodiacetate + glyoxylate + FMN + H2O

two-component alkanesulfonate monooxygenase :
an alkylsulfonate + FMNH2 + oxygen → an aldehyde + sulfite + FMN + H2O + 2 H+

uracil degradation III :
uracil + FMNH2 + oxygen → (Z)-3-ureidoacrylate peracid + FMN + H+

Not in pathways:
isethionate + FMNH2 + oxygen → glycolaldehyde + sulfite + FMN + H2O + 2 H+
1-butanesulfonate + FMNH2 + oxygen → butanal + sulfite + FMN + H2O + 2 H+
thymine + FMNH2 + oxygen → (Z)-2-methylureidoacrylate peracid + FMN + H+
3-(N-morpholino)propanesulfonate + FMNH2 + oxygen → 3-(N-morpholino)propanal + sulfite + FMN + H2O + 2 H+
dimethyl sulfone + FMNH2 + oxygen → methylsulfonyl + formaldehyde + FMN + H2O + H+
methylsulfonyl + FMNH2 + oxygen → methanesulfonate + FMN + H2O + 2 H+

Not in pathways:
2-methylpropanamine + a reduced flavin + oxygen → N-(2-methylpropyl)hydroxylamine + an oxidized flavin + H2O + H+

In Reactions of unknown directionality:

Not in pathways:
FAD + H2O = AMP + FMN + 2 H+
riboflavin + α-D-glucopyranose 1-phosphate = D-glucopyranose + FMN
2-amino-4-deoxy-chorismate + FMN = 3-(1-carboxyvinyloxy)anthranilate + FMNH2

Not in pathways:
a reduced flavin + NAD+ = an oxidized flavin + NADH + H+

In Transport reactions:

Enzymes activated by FMN, sorted by the type of activation, are:

Activator (Mechanism unknown) of: (S)-2-hydroxypropylphosphonate epoxidase [Liu01a]

Enzymes inhibited by FMN, sorted by the type of inhibition, are:

Inhibitor (Mechanism unknown) of: cannabichromenate synthase [Morimoto98]

This compound has been characterized as a cofactor or prosthetic group of the following enzymes: L-lactate dehydrogenase, glycerol-3-phosphate dehydrogenase, anaerobic, protoporphyrinogen dehydrogenase, 4'-phosphopantothenoylcysteine decarboxylase, dihydroorotate dehydrogenase, pyridoxamine 5'-phosphate oxidase, pyridoxine 5'-phosphate oxidase, NADH:ubiquinone oxidoreductase (H+-transporting), flavin reductase, sulfite reductase, NADH-azoreductase, N-ethylmaleimide reductase, chromate reductase, NAD(P)H:quinone oxidoreductase, quinone oxidoreductase, uracil oxygenase, NADH dehydrogenase (quinone), 2,4-dienoyl-CoA reductase, NAD(P)H nitroreductase, NADPH nitroreductase NfsA, 3-succinoylsemialdehyde-pyridine dehydrogenase, pseudooxynicotine oxidase, coenzyme F420H2 oxidase, 4-hydroxy-2,2'-bipyrrole-5-methanol dehydrogenase, methylene tetrahydrofolate reductase, dihydromethanopterin reductase (acceptor), NADPH-cytochrome P540 reductase, NADPH-cytochrome P450 reductase, 1,2-dinitroglycerin reductase (2-mononitroglycerol forming), 1,2-dinitroglycerol reductase (1-mononitroglycerol forming), 1,3-dinitroglycerol reductase, nitroglycerin reductase (1,2-dinitroglycerol forming), nitroglycerin reductase (1,2-dinitroglycerol-forming), 2-naphthoyl-CoA reductase, pyridoxine 5'-phosphate oxidase, urocanate reductase, crotonyl-[acyl-carrier-protein] reductase (NADH), enoyl-[acyl-carrier-protein] reductase (NADH), enoyl-[acyl-carrier-protein] reductase (NADH), chanoclavine-I aldehyde dehydrogenase, FMN reductase [NAD(P)H], nicotine dehydrogenase, NAD(P)H-nicotine blue oxidoreductase, 3,6-diketocamphane 1,6-monooxygenase, 2,5-diketocamphane 1,2-monooxygenase, 5-hydroxyadamantan-2-one monooxygenase, adamantanone-monooxygenase, N-methyl-L-glutamate synthase, N-methyl-L-glutamate synthase, FMN reductase (NADPH), aminopyrrolnitrin oxygenase, hydrogen dehydrogenase, hydrogenase, indole-3-acetaldehyde oxidase, indolepyruvate decarboxylase, sulfite reductase, ethylnitronate monooxygenase, 4-toluene-sulfonate monooxygenase, nitroglycerin reductase (1,3-dinitroglycerol-forming), nitroglycerin reductase (1,3-dinitroglycerol forming), lactyl-CoA dehydratase, (S)-2-hydroxy-2-phenylacetate:acceptor 2-oxidoreductase, dihydroorotate dehydrogenase, 2-nitrobenzoate nitroreductase, nitrobenzene nitroreductase, trimethylamine dehydrogenase, (S)-2-hydroxy-2-(4-hydroxyphenyl)acetate:acceptor 2-oxidoreductase, NAD(P)H: plastoquinone dehydrogenase, formate dehydrogenase, phenazine-1-carboxylate synthase, 4-benzoquinone reductase, sulfolactate dehydrogenase, hydroxybenzoquinone reductase, isopentenyl-diphosphate δ-isomerase, dihydroorotate dehydrogenase, dihydroorotate dehydrogenase, methanesulfonate monooxygenase, NADPH-cytochrome P450 reductase, NADPH-cytochrome P450 reductase, NADH:FMN oxidoreductase, 4-sulfobenzoate 3,4-dioxygenase, cob(II)yrinate a,c-diamide reductase, glutamate synthase, glutamate synthase, dirigent protein, acryloyl-CoA reductase, 4-hydroxy-tetrahydrodipicolinate reductase, NAD-dependent formate dehydrogenase, NAD-dependent formate dehydrogenase, xanthine dehydrogenase, nitric-oxide synthase, nitric oxide synthase, nitric-oxide synthase, sarcosine oxidase, L-arginine decarboxyoxidase

This compound has been characterized as an alternative substrate of the following enzymes: thiol oxidase, pyridoxal phosphatase, flavin:NADH reductase, pyruvate-ferredoxin oxidoreductase, pyruvate:ferredoxin oxidoreductase, riboflavin reductase, NADH-dependent flavin reductase, hydrogenase, guanosine-5'-phosphate phosphohydrolase


Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Liu01a: Liu P, Murakami K, Seki T, He X, Yeung SM, Kuzuyama T, Seto H, Liu H (2001). "Protein purification and function assignment of the epoxidase catalyzing the formation of fosfomycin." J Am Chem Soc 123(19);4619-20. PMID: 11457256

Morimoto98: Morimoto S, Komatsu K, Taura F, Shoyama Y (1998). "Purification and characterization of cannabichromenic acid synthase from Cannabis sativa." Phytochemistry 49(6);1525-9. PMID: 9862135

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Fri Nov 27, 2015, biocyc12.