NAD(P)H dehydrogenase, quinone 2, also known as QR2, is a protein that in humans is encoded by the NQO2 gene. It is a phase II detoxification enzyme which can carry out two or four electron reductions of quinones. Its mechanism of reduction is through a ping-pong mechanism involving its FAD cofactor. Initially in a reductive phase NQO2 binds to reduced dihydronicotinamide riboside (NRH) electron donor, and mediates a hydride transfer from NRH to FAD. Then, in an oxidative phase, NQO2 binds to its quinone substrate and reduces the quinone to a dihydroquinone. Besides the two catalytic FAD, NQO2 also has two zinc ions. It is not clear whether the metal has a catalytic role. NQO2 is a paralog of NQO1.

Quick Facts NQO2, Available structures ...

NQO2
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1QR2, 1SG0, 1XI2, 1ZX1, 2BZS, 2QMY, 2QMZ, 2QR2, 2QWX, 2QX4, 2QX6, 2QX8, 2QX9, 3FW1, 3G5M, 3GAM, 3NFR, 3NHF, 3NHJ, 3NHK, 3NHL, 3NHP, 3NHR, 3NHS, 3NHU, 3NHW, 3NHY, 3O2N, 3O73, 3OVM, 3OWH, 3OWX, 3OX1, 3OX2, 3OX3, 3TE7, 3TEM, 3TZB, 3UXE, 3UXH, 4FGJ, 4FGK, 4FGL, 4GQI, 4GR9, 4QOD, 4QOE, 4QOF, 4QOG, 4QOH, 4QOI, 4QOJ, 4U7F, 4U7G, 4U7H, 4XDG, 4XDH, 4ZVL, 4ZVM, 4ZVK, 5LBT, 5LBU, 5BUC, 4ZVN
Identifiers
Aliases	NQO2, Nqo2, NMO2, Nmor2, Ox2, DHQV, DIA6, QR2, NAD(P)H quinone dehydrogenase 2, N-ribosyldihydronicotinamide:quinone reductase 2
External IDs	OMIM: 160998 MGI: 104513 HomoloGene: 696 GeneCards: NQO2
Gene location (Human) Chr. Chromosome 6 (human)[1] Band 6p25.2 Start 2,987,987 bp[1] End 3,019,755 bp[1]
Gene location (Mouse) Chr. Chromosome 13 (mouse)[2] Band 13 A3.3|13 14.01 cM Start 34,148,670 bp[2] End 34,172,426 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in left adrenal gland right adrenal gland kidney triceps brachii muscle right lobe of liver gastrocnemius muscle kidney tubule right coronary artery left ventricle left coronary artery Top expressed in left lobe of liver seminiferous tubule submandibular gland proximal tubule sternocleidomastoid muscle endocardial cushion lacrimal gland jejunum duodenum Paneth cell More reference expression data BioGPS More reference expression data
Gene ontology Molecular function protein binding metal ion binding dihydronicotinamide riboside quinone reductase activity zinc ion binding electron transfer activity oxidoreductase activity oxidoreductase activity, acting on other nitrogenous compounds as donors chloride ion binding protein homodimerization activity FAD binding melatonin binding resveratrol binding NAD(P)H dehydrogenase (quinone) activity Cellular component extracellular exosome nucleoplasm cytoplasm cytosol Biological process memory positive regulation of neuron apoptotic process positive regulation of vascular associated smooth muscle cell proliferation positive regulation of ERK1 and ERK2 cascade positive regulation of reactive oxygen species metabolic process xenobiotic metabolic process electron transport chain Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 4835 18105 Ensembl ENSG00000124588 ENSMUSG00000046949 UniProt P16083 Q9JI75 RefSeq (mRNA) NM_000904 NM_001290221 NM_001290222 NM_001318940 NM_001163239 NM_001163241 NM_001163242 NM_020282 RefSeq (protein) NP_000895 NP_001277150 NP_001277151 NP_001305869 NP_001156711 NP_001156713 NP_001156714 NP_064678 Location (UCSC) Chr 6: 2.99 – 3.02 Mb Chr 13: 34.15 – 34.17 Mb PubMed search [3] [4]
Wikidata
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NQO2 is a homodimer. NQO2 can be inhibited by resveratrol.^[5] One of QR2's binding sites responds to 2-iodomelatonin, and has been referred to as MT₃.^[6]