FMN-dependent dehydrogenase (IPR000262)

Short name: FMN-dep_DH

Overlapping homologous superfamilies

Domain relationships


A number of oxidoreductases that act on alpha-hydroxy acids and which are FMN-containing flavoproteins have been shown [PMID: 2324094, PMID: 2271624, PMID: 1939137] to be structurally related. These enzymes are:

  • Lactate dehydrogenase (EC:, which consists of a dehydrogenase domain and a haem-binding domain called cytochrome b2 and which catalyses the conversion of lactate into pyruvate.
  • Glycolate oxidase (EC: ((S)-2-hydroxy-acid oxidase), a peroxisomal enzyme that catalyses the conversion of glycolate and oxygen to glyoxylate and hydrogen peroxide.
  • Long chain alpha-hydroxy acid oxidase from rat (EC:, a peroxisomal enzyme.
  • Lactate 2-monooxygenase (EC: (lactate oxidase) from Mycobacterium smegmatis, which catalyses the conversion of lactate and oxygen to acetate, carbon dioxide and water.
  • (S)-mandelate dehydrogenase from Pseudomonas putida (gene mdlB), which catalyses the reduction of (S)-mandelate to benzoylformate.

The first step in the reaction mechanism of these enzymes is the abstraction of the proton from the alpha-carbon of the substrate producing a carbanion which can subsequently attach to the N5 atom of FMN. A conserved histidine has been shown [PMID: 2644287] to be involved in the removal of the proton. The region around this active site residue is highly conserved and contains an arginine residue which is involved in substrate binding.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0016491 oxidoreductase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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