MetaCyc

Parent Class:

EC-Numbers → 1 -- Oxidoreductases → 1.1 -- Acting on the CH-OH group of donors → 1.1.5 -- With a quinone or similar compound as acceptor

Synonyms: FAD-dependent malate-vitamin K reductase, malate-vitamin K reductase, (S)-malate:(acceptor) oxidoreductase, L-malate-quinone oxidoreductase, malate:quinone oxidoreductase, malate quinone oxidoreductase, MQO, malate:quinone reductase, malate dehydrogenase (acceptor), FAD-dependent malate dehydrogenase

Systematic Name: (S)-malate:quinone oxidoreductase

Unification Links: BRENDA:1.1.5.4, ENZYME:1.1.5.4, IUBMB-ExplorEnz:1.1.5.4

Supersedes EC numbers: 1.1.3.3, 1.1.99.16

Reaction:
(S)-malate + electron-transfer quinone_{[inner membrane]} ↔ oxaloacetate + electron-transfer quinol_{[inner membrane]}

Unofficial Reactions:
menaquinone-9_[membrane] + (S)-malate_[in] → menaquinol-9_[membrane] + oxaloacetate_[in],
(S)-malate + a menaquinone → oxaloacetate + a menaquinol,
a menaquinone_[membrane] + (S)-malate_[in] → a menaquinol_[membrane] + oxaloacetate_[in]

Enzymes and Genes:
malate:quinone oxidoreductase: mqo ( Escherichia coli K-12 substr. MG1655 )

Summary:
A flavoprotein (FAD). There are several forms of malate dehydrogenases that differ in their use of substrates and cofactors. This enzyme can use Vitamin K and several other quinones as acceptors. Different from EC 1.1.1.37, malate dehydrogenase; EC 1.1.1.82, malate dehydrogenase (NADP⁺); and EC 1.1.1.299, malate dehydrogenase [NAD(P)⁺].

Citations: [Prasada75, Imai78, Molenaar98, Kather00]