Flavin monooxygenase (FMO) 2 (IPR002254)

Short name: Flavin_mOase_2

Overlapping homologous superfamilies


Family relationships


Flavin-containing monooxygenases (FMOs) constitute a family of xenobiotic- metabolising enzymes [PMID: 8311461]. Using an NADPH cofactor and FAD prosthetic group, these microsomal proteins catalyse the oxygenation of nucleophilic nitrogen, sulphur, phosphorous and selenium atoms in a range of structurally diverse compounds. Five mammalian forms of FMO are now known and have been designated FMO1-FMO5 [PMID: 1712018, PMID: 2318837, PMID: 1542660, PMID: 1417778, PMID: 8486656].

Cavia porcellus (Guinea pig) and Oryctolagus cuniculus (Rabbit) both express two variants of 'lung' FMO, observed as three distinct phenotypes based on mobility differences in SDS-PAGE [PMID: 1306120]. The coding regions of the guinea pig variants differ at only two positions, both of which result in amino acid substitutions [PMID: 1306120]. Similarly, the nucleotide and amino acid sequences of the rabbit variants differ at only two positions. The amino sequence contains putative FAD- (GxGxxG) and NADP+- binding (GxGxxA) sites, a 'FATGY' motif that has also been observed in a range of siderphore biosynthetic enzymes [PMID: 9538688], and a C-terminal hydrophobic segment that is believed to anchor the monooxygenase to the microsomal membrane [PMID: 2355001]. The activities of the enzymes are characteristic of the lung FMO, and the mobilities of the expressed enzymes are the same as those observed for the variants present in guinea pig pulmonary microsomal preparations [PMID: 1306120]. Both rabbit and guinea pig lung FMO are associated with a single gene. Rabbit lung FMO exists in tight association with the calcium-binding protein, calreticulin [PMID: 1911780]. It is thought that complexation of calreticulin with rabbit lung FMO could account for some of the unusual physical properties of this FMO enzyme form.

GO terms

Biological Process

GO:0055114 oxidation-reduction process

Molecular Function

GO:0004499 N,N-dimethylaniline monooxygenase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.