FMN hydroxy acid dehydrogenase domain (IPR037396)
Short name: FMN_HAD
Overlapping homologous superfamilies
- Aldolase-type TIM barrel (IPR013785)
- FMN-dependent dehydrogenase (IPR000262)
- FMN hydroxy acid dehydrogenase domain (IPR037396)
A number of oxidoreductases that act on alpha-hydroxy acids and which are FMN-containing flavoproteins have been shown to be structurally related [PMID: 2324094, PMID: 2271624, PMID: 1939137, PMID: 15683236]; these enzymes are:
- Lactate dehydrogenase (EC:220.127.116.11), which consists of a dehydrogenase domain and a heme-binding domain called cytochrome b2 and which catalyzes the conversion of lactate into pyruvate.
- Glycolate oxidase (EC:18.104.22.168) ((S)-2-hydroxy-acid oxidase), a peroxisomal enzyme that catalyzes the conversion of glycolate and oxygen to glyoxylate and hydrogen peroxide.
- Long chain alpha-hydroxy acid oxidase from rat (EC:22.214.171.124), a peroxisomal enzyme.
- Lactate 2-monooxygenase (EC:126.96.36.199) (lactate oxidase) from Mycobacterium smegmatis, which catalyzes the conversion of lactate and oxygen to acetate, carbon dioxide and water.
- (S)-mandelate dehydrogenase from Pseudomonas putida (gene mdlB), which catalyzes 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. Three-dimensional structures of FMN-dependent alpha-hydroxy acid dehydrogenases show a common fold with a TIM barrel structure.
This entry represents the FMN hydroxy acid dehydrogenase domain.
- PS51349 (FMN_HYDROXY_ACID_DH_2)