Article · Wikipedia archive · Last revised Jun 21, 2026

FMO2

Flavin-containing monooxygenase 2 (FMO2), also known as dimethylaniline monooxygenase [N-oxide-forming] 2, is a mammalian enzyme that in humans is encoded by the FMO2 gene. The gene is found in a cluster with the FMO1, FMO3, and FMO4 genes on chromosome 1.

Last revised
Jun 21, 2026
Read time
≈ 4 min
Length
837 w
Citations
18
Source
FMO2
Identifiers
AliasesFMO2, FMO1B1, flavin containing monooxygenase 2, flavin containing dimethylaniline monoxygenase 2
External IDsOMIM: 603955; MGI: 1916776; HomoloGene: 86882; GeneCards: FMO2; OMA:FMO2 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001301347
NM_001460
NM_001365900

NM_018881
NM_001360913
NM_001360914

RefSeq (protein)

NP_001288276
NP_001451
NP_001352829

NP_061369
NP_001347842
NP_001347843

Location (UCSC)Chr 1: 171.19 – 171.21 MbChr 1: 162.7 – 162.73 Mb
PubMed search34
Wikidata
View/Edit HumanView/Edit Mouse

Flavin-containing monooxygenase 2 (FMO2), also known as dimethylaniline monooxygenase [N-oxide-forming] 2, is a mammalian enzyme that in humans is encoded by the FMO2 gene.567 The gene is found in a cluster with the FMO1, FMO3, and FMO4 genes on chromosome 1.7

FMO2 is a member of the family of flavin-containing monooxygenases, NADPH-dependent enzymes that catalyze the oxidation of many drugs and xenobiotics. It catalyzes the N-oxidation of some primary alkylamines through an N-hydroxylamine intermediate.7

In humans, FMO2 is expressed in lung tissue.8 The most common isoform, FMO2*2A, contains a premature stop codon, leading to a truncated protein with no catalytic activity that is probably rapidly degraded.7 The other isoform, FMO2*1, present in sub-Saharan Africans (up to 50%), African-Americans (26%) and Hispanics (2–7%), is functional.89 Its substrates include thioether-containing pesticides, the anti-tuberculosis drug ethionamide, as well as α-naphthylthiourea and other thioureas.9

References

References

  1. GRCh38: Ensembl release 89: ENSG00000094963Ensembl, May 2017
  2. GRCm38: Ensembl release 89: ENSMUSG00000040170Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. Dolphin CT, Shephard EA, Povey S, Smith RL, Phillips IR (Nov 1992). "Cloning, primary sequence and chromosomal localization of human FMO2, a new member of the flavin-containing mono-oxygenase family". The Biochemical Journal. 287. ( Pt 1) (Pt 1): 261–267. doi:10.1042/bj2870261. PMC 1133153. PMID 1417778.
  6. Dolphin CT, Beckett DJ, Janmohamed A, Cullingford TE, Smith RL, Shephard EA, et al. (Dec 1998). "The flavin-containing monooxygenase 2 gene (FMO2) of humans, but not of other primates, encodes a truncated, nonfunctional protein". The Journal of Biological Chemistry. 273 (46): 30599–30607. doi:10.1074/jbc.273.46.30599. PMID 9804831.
  7. "Entrez Gene: FMO2 flavin containing monooxygenase 2 (non-functional)".
  8. Online Mendelian Inheritance in Man (OMIM): 603955
  9. Veeramah KR, Thomas MG, Weale ME, Zeitlyn D, Tarekegn A, Bekele E, et al. (October 2008). "The potentially deleterious functional variant flavin-containing monooxygenase 2*1 is at high frequency throughout sub-Saharan Africa". Pharmacogenetics and Genomics. 18 (10): 877–886. doi:10.1097/fpc.0b013e3283097311. PMC 2666332. PMID 18794725.
Further reading

Further reading