Escherichia coli K-12 substr. MG1655 Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By Conversion TypeSimple ReactionsChemical ReactionsComposite ReactionsElectron-Transfer-Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:

Enzymes and Genes:
NADPH quinone reductaseInferred from experiment: mdaB

Supersedes EC number:

Transport reaction diagram

Reaction Locations: inner membrane (sensu Gram-negative Bacteria)

The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.

Most BioCyc compounds have been protonated to a reference pH value of 7.3. Please see the PGDB Concepts Guide for more information.

Mass balance status: Balanced.

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, Hayashi90]. 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].

Gene-Reaction Schematic

Gene-Reaction Schematic

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:


Hayashi90: 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

Koli69: Koli AK, Yearby C, Scott W, Donaldson KO (1969). "Purification and properties of three separate menadione reductases from hog liver." J Biol Chem 244(4);621-9. PMID: 4388793

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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