NQO2
Description
The NQO2 (N-ribosyldihydronicotinamide:quinone dehydrogenase 2) is a protein-coding gene located on chromosome 6.
NQO2, also known as QR2, is a protein encoded by the NQO2 gene in humans. It acts as a phase II detoxification enzyme, capable of reducing quinones through two or four electron transfers. Its reduction mechanism involves a ping-pong mechanism utilizing its FAD cofactor. First, NQO2 binds to the reduced dihydronicotinamide riboside (NRH) electron donor and facilitates a hydride transfer from NRH to FAD. Subsequently, in an oxidative phase, NQO2 binds to its quinone substrate and reduces it to a dihydroquinone. Besides the two catalytic FAD molecules, NQO2 also possesses two zinc ions, although their catalytic role remains unclear. NQO2 is a paralog of NQO1 and forms a homodimer. NQO2 can be inhibited by resveratrol, and one of its binding sites, referred to as MT3, interacts with 2-iodomelatonin.
NQO2 acts as a quinone reductase, playing a crucial role in detoxification pathways by facilitating conjugation reactions of hydroquinones. It also participates in biosynthetic processes like the vitamin K-dependent gamma-carboxylation of glutamate residues during prothrombin synthesis.
NQO2 is also known as DHQV, DIA6, NMOR2, QR2.
