|Gene:||mdaB||Accession Numbers: EG12656 (EcoCyc), b3028, ECK3019|
Subunit composition of
NADPH quinone reductase = [MdaB]2
NADPH quinone reductase monomer = MdaB
The MdaB quinone reductase is specific for NADPH and is most active with quinone derivatives and ferricyanide as electron acceptors [Hayashi96]. In vitro, YgiN is able to reoxidize menadiol that has been reduced by MdaB quinone reductase; the two enzymes may form a quinone redox cycle. The biological role of a quinone redox cycle may be to maintain an intracellular pool of menadione and ubiquinone using a catalytic mechanism that avoids the formation of a semiquinone intermediate, and to act as a quinone buffer [Adams05].
Despite the different cofactor and cosubstrate requirements, it was later stated that MdaB is identical to NADH dehydrogenase (quinone) [Adams05], but no evidence was given. Unlike MdaB, NADH dehydrogenase (quinone) was shown to utilize NADH and to be FMN-dependent [Hayashi90]. Menadione specifically induces expression of the NADH- and FMN-dependent activity, while 2-methylene-4-butyrolactone (MBL) and other compounds containing a methide group induce expression of the NADPH-dependent MdaB activity [Hayashi96].
Overexpression of mdaB leads to increased resistance to the tumoricidal agent DMP 840 [Chatterjee95a]. A strain adapted for growth in benzalkonium chloride overexpresses MdaB [Bore07]. An mdaB null mutant shows no change in sensitivity to menadione-induced oxidative stress [Adams06].
MdaB: "modulator of drug activity B" [Chatterjee95a]
|Map Position: [3,170,552 -> 3,171,133] (68.34 centisomes)||Length: 582 bp / 193 aa|
Molecular Weight of Polypeptide: 21.891 kD (from nucleotide sequence), 21 kD (experimental) [Hayashi96 ]
Molecular Weight of Multimer: 42 kD (experimental) [Hayashi96]
Unification Links: ASAP:ABE-0009946 , EchoBASE:EB2524 , EcoGene:EG12656 , EcoliWiki:b3028 , ModBase:P0AEY5 , OU-Microarray:b3028 , PortEco:mdaB , PR:PRO_000023173 , Pride:P0AEY5 , Protein Model Portal:P0AEY5 , RefSeq:NP_417500 , RegulonDB:EG12656 , SMR:P0AEY5 , String:511145.b3028 , UniProt:P0AEY5
In Paralogous Gene Group: 18 (3 members)
|Biological Process:||GO:0055114 - oxidation-reduction process [Hayashi96]|
|Molecular Function:||GO:0008753 - NADPH dehydrogenase (quinone) activity
GO:0050660 - flavin adenine dinucleotide binding [Adams06]
|Cellular Component:||GO:0005829 - cytosol [Ishihama08]|
|MultiFun Terms:||cell processes → protection → drug resistance/sensitivity|
|metabolism → energy production/transport → electron donors|
|Growth Medium||Growth?||T (°C)||O2||pH||Osm/L||Growth Observations|
|LB enriched||Yes||37||Aerobic||6.95||Yes [Gerdes03, Comment 1]|
|LB Lennox||Yes||37||Aerobic||7||Yes [Baba06, Comment 2]|
|M9 medium with 1% glycerol||Yes||37||Aerobic||7.2||0.35||Yes [Joyce06, Comment 3]|
|MOPS medium with 0.4% glucose||Yes||37||Aerobic||7.2||0.22||Yes [Baba06, Comment 2] |
Yes [Feist07, Comment 4]
Enzymatic reaction of: NADPH quinone reductase
Synonyms: NADPH-specific quinone reductase, NADPH dehydrogenase (quinone), NADPH:(quinone-acceptor) oxidoreductase
EC Number: 22.214.171.124
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.
The reaction is physiologically favored in the direction shown.
Amino-terminal sequence determination of the purified enzyme showed it to be the product of the mdaB gene. The enzyme can be purified in two forms which differ in FAD content and charge [Hayashi96].
pH(opt): 7 [Hayashi96]
10/20/97 Gene b3028 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG12656; confirmed by SwissProt match.
Adams05: Adams MA, Jia Z (2005). "Structural and biochemical evidence for an enzymatic quinone redox cycle in Escherichia coli: identification of a novel quinol monooxygenase." J Biol Chem 280(9);8358-63. PMID: 15613473
Adams05a: Adams MA, Iannuzzi P, Jia Z (2005). "MdaB from Escherichia coli: cloning, purification, crystallization and preliminary X-ray analysis." Acta Crystallograph Sect F Struct Biol Cryst Commun 61(Pt 2);235-8. PMID: 16511004
Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554
Bore07: Bore E, Hebraud M, Chafsey I, Chambon C, Skjaeret C, Moen B, Moretro T, Langsrud O, Rudi K, Langsrud S (2007). "Adapted tolerance to benzalkonium chloride in Escherichia coli K-12 studied by transcriptome and proteome analyses." Microbiology 153(Pt 4);935-46. PMID: 17379704
Chatterjee95a: Chatterjee PK, Sternberg NL (1995). "A general genetic approach in Escherichia coli for determining the mechanism(s) of action of tumoricidal agents: application to DMP 840, a tumoricidal agent." Proc Natl Acad Sci U S A 92(19);8950-4. PMID: 7568050
Feist07: Feist AM, Henry CS, Reed JL, Krummenacker M, Joyce AR, Karp PD, Broadbelt LJ, Hatzimanikatis V, Palsson BO (2007). "A genome-scale metabolic reconstruction for Escherichia coli K-12 MG1655 that accounts for 1260 ORFs and thermodynamic information." Mol Syst Biol 3;121. PMID: 17593909
Gerdes03: Gerdes SY, Scholle MD, Campbell JW, Balazsi G, Ravasz E, Daugherty MD, Somera AL, Kyrpides NC, Anderson I, Gelfand MS, Bhattacharya A, Kapatral V, D'Souza M, Baev MV, Grechkin Y, Mseeh F, Fonstein MY, Overbeek R, Barabasi AL, Oltvai ZN, Osterman AL (2003). "Experimental determination and system level analysis of essential genes in Escherichia coli MG1655." J Bacteriol 185(19);5673-84. PMID: 13129938
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
Hayashi96: 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
Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394
Martin11: Martin RG, Rosner JL (2011). "Promoter discrimination at class I MarA regulon promoters mediated by glutamic acid 89 of the MarA transcriptional activator of Escherichia coli." J Bacteriol 193(2);506-15. PMID: 21097628
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