|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 22.214.171.124
Enzymes and Genes:
NADPH quinone reductase : mdaB ( Escherichia coli K-12 substr. MG1655 )
NAD(P)H dehydrogenase : nda2 ( Chlamydomonas reinhardtii )
chromate reductase : yieF ( Escherichia coli K-12 substr. MG1655 )
regulator of KefC-mediated potassium transport and quinone oxidoreductase : kefF ( Escherichia coli K-12 substr. MG1655 )
NAD(P)H:quinone oxidoreductase : wrbA ( Escherichia coli K-12 substr. MG1655 )
Supersedes EC number: 126.96.36.199
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Direct generic reaction:
a quinone + NAD(P)H + H+ → a quinol + NAD(P)+ (188.8.131.52)
Enzyme Commission Primary Name: NADPH dehydrogenase (quinone)
Enzyme Commission Synonyms: reduced nicotinamide adenine dinucleotide phosphate (quinone) dehydrogenase, NADPH oxidase, NADPH2 dehydrogenase (quinone)
Enzyme Commission Summary:
A flavoprotein [Koli69, Hayashi90a]. The enzyme from Escherichia coli is specific for NADPH and is most active with quinone derivatives and ferricyanide as electron acceptors [Hayashi96a]. Menaquinone can act as acceptor. The enzyme from hog liver is inhibited by dicoumarol and folic acid derivatives but not by 2,4-dinitrophenol [Koli69].
Hayashi90a: Hayashi M, Hasegawa K, Oguni Y, Unemoto T (1990). "Characterization of FMN-dependent NADH-quinone reductase induced by menadione in Escherichia coli." Biochim Biophys Acta 1990;1035(2);230-6. PMID: 2118386
Hayashi96a: Hayashi M, Ohzeki H, Shimada H, Unemoto T (1996). "NADPH-specific quinone reductase is induced by 2-methylene-4-butyrolactone in Escherichia coli." Biochim Biophys Acta 1273(2);165-70. PMID: 8611590
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