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discounted EARLY registration ends Dec 31, 2014
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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
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for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
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MetaCyc Enzyme: methylglyoxal reductase [multifunctional]

Gene: dkgA Accession Numbers: G7565 (MetaCyc), b3012, ECK3004

Synonyms: yqhE, AKR5C2

Species: Escherichia coli K-12 substr. MG1655

Summary:
DkgA belongs to the aldo-keto reductase (AKR) family and has been shown to have methylglyxoal reductase [Ko05] and beta-keto ester reductase [Habrych02] activity.

dkgA was reported to encode 2,5-diketo-D-gluconate reductase (25DKGR) A, one of two 25DKG reductases in E. coli. The enzyme uses NADPH as the preferred electron donor and was thought to be involved in ketogluconate metabolism [Yum99]. The specific activity of the enzyme towards 2,5-diketo-D-gluconate was reported to be almost 1000-fold lower than its activity towards methylglyoxal [Ko05].

In a mutant of the ethanologenic E. coli strain LY180 that was selected for furfural resistance, dkgA expression is decreased. Expression of dkgA in this mutant decreases furfural tolerance [Miller09]. Due to its low Km for NADPH, reduction of furans by DkgA may deplete NADPH pools and thereby limit cellular biosynthesis [Miller10a]. A broad survey of aldehyde reductases showed that DkgA was one of several endogenous aldehyde reductases that contribute to the degradation of desired aldehyde end products of metabolic engineering [Rodriguez14].

A crystal structure of DkgA has been solved at 2.16 Å resolution [Jeudy06].

Expression of dkgA is not increased in response to methylglyoxal [Ko05].

Review: [Lapthorn13]

Locations: cytosol

Map Position: [3,154,645 -> 3,155,472]

Molecular Weight of Polypeptide: 31.11 kD (from nucleotide sequence), 29.0 kD (experimental) [Yum99 ]

Unification Links: ASAP:ABE-0009892 , EchoBASE:EB2835 , EcoGene:EG13015 , EcoliWiki:b3012 , ModBase:Q46857 , OU-Microarray:b3012 , PortEco:dkgA , PR:PRO_000022451 , Pride:Q46857 , Protein Model Portal:Q46857 , RefSeq:NP_417485 , RegulonDB:G7565 , SMR:Q46857 , String:511145.b3012 , Swiss-Model:Q46857 , UniProt:Q46857

Relationship Links: InterPro:IN-FAMILY:IPR001395 , InterPro:IN-FAMILY:IPR018170 , InterPro:IN-FAMILY:IPR020471 , InterPro:IN-FAMILY:IPR023210 , Panther:IN-FAMILY:PTHR11732 , PDB:Structure:1MZR , Pfam:IN-FAMILY:PF00248 , Prints:IN-FAMILY:PR00069 , Prosite:IN-FAMILY:PS00062 , Prosite:IN-FAMILY:PS00063 , Prosite:IN-FAMILY:PS00798

Gene-Reaction Schematic: ?

Instance reactions of [an alcohol + NADP+ = an aldehyde + NADPH + H+] (1.1.1.2):
i1: n-butanol + NADP+ ↔ butanal + NADPH + H+ (1.1.1.-)

i2: trans-2-pentenol + NADP+trans-2-pentenal + NADPH + H+ (1.1.1.-)

i3: glycerol + NADP+ = D-glyceraldehyde + NADPH + H+ (1.1.1.72/1.1.1.372)

i4: glycerol + NADP+ ← L-glyceraldehyde + NADPH + H+ (1.1.1.372)

i5: ethanol + NADP+ = acetaldehyde + NADPH + H+ (1.1.1.2)

i6: (2E,6E)-farnesol + NADP+ ↔ (2E,6E)-farnesal + NADPH + H+ (1.1.1.216)

i7: galactitol + NADP+ ↔ β-D-galactose + NADPH + H+ (1.1.1.21)

i8: (R)-propane-1,2-diol + NADP+ ← (R)-lactaldehyde + NADPH + H+ (1.1.1.-)

i9: (S)-propane-1,2-diol + NADP+ ← (S)-lactaldehyde + NADPH + H+ (1.1.1.-)

i10: (S)-propane-1,2-diol + NADP+ = (S)-lactaldehyde + NADPH + H+ (1.1.1.55)

i11: trans-2-hexenol + NADP+ ← trans-2-hexenal + NADPH + H+ (1.1.1.-)

i12: (6E)-8-oxogeraniol + NADP+ ↔ (6E)-8-oxogeranial + NADPH + H+ (1.1.1.-)

i13: (6E)-8-hydroxygeranial + NADP+ → (6E)-8-oxogeranial + NADPH + H+ (1.1.1.-)

i14: geraniol + NADP+ → geranial + NADPH + H+ (1.1.1.183)

GO Terms:

Biological Process: GO:0051596 - methylglyoxal catabolic process Inferred from experiment [Ko05]
GO:0019853 - L-ascorbic acid biosynthetic process Inferred by computational analysis [UniProtGOA11]
GO:0055114 - oxidation-reduction process Inferred by computational analysis [UniProtGOA11, GOA01]
Molecular Function: GO:0008106 - alcohol dehydrogenase (NADP+) activity Inferred from experiment [Rodriguez14]
GO:0016616 - oxidoreductase activity, acting on the CH-OH group of donors, NAD or NADP as acceptor Inferred from experiment [Ko05]
GO:0016491 - oxidoreductase activity Inferred by computational analysis [UniProtGOA11, GOA01]
GO:0050580 - 2,5-didehydrogluconate reductase activity Inferred by computational analysis [GOA01a]
Cellular Component: GO:0005829 - cytosol Inferred from experiment Inferred by computational analysis [DiazMejia09, LopezCampistrou05]
GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11a, UniProtGOA11]

MultiFun Terms: metabolism carbon utilization carbon compounds
metabolism central intermediary metabolism methylglyoxal metabolism

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International


Enzymatic reaction of: methylglyoxal reductase

EC Number: 1.1.1.-

acetol + NADP+ <=> methylglyoxal + NADPH + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is physiologically favored in the opposite direction.

Alternative Substrates for methylglyoxal: glyoxal [Lee13b ] , glycolaldehyde [Lee13b ] , furfural [Miller09 ] , phenylglyoxal [Ko05 ]

In Pathways: superpathway of methylglyoxal degradation , methylglyoxal degradation III

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International

Kinetic Parameters:

Substrate
Km (μM)
kcat (sec-1)
kcat/Km (sec-1 μM-1)
Citations
glycolaldehyde
12000.0
0.25
[Lee13b]
furfural
130000.0
[Miller09]
methylglyoxal
2050.0
27.62
[Ko05]
NADPH
23.0
[Miller09]
glyoxal
22000.0
4.93
[Lee13b]


Enzymatic reaction of: isobutyraldehyde reductase

EC Number: 1.1.1.-

isobutanol + NADP+ <=> isobutanal + NADPH + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Reversibility of this reaction is unspecified.

Alternative Substrates for isobutanal: hexanal [Rodriguez14 ] , octanal [Rodriguez14 ]

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International


Enzymatic reaction of: β-keto ester reductase

EC Number: 1.1.1.-

ethyl-(2R)-methyl-(3S)-hydroxybutanoate + NADP+ <=> ethyl-2-methylacetoacetate + NADPH + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Reversibility of this reaction is unspecified.

Alternative Substrates for ethyl-2-methylacetoacetate: ethyl-acetoacetate [Habrych02 ]

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International

Summary:
The enzyme was purified from E. coli BL21(DE3) [Habrych02]. The protein sequence of the K-12 MG1655 enzyme is identical.

Kinetic Parameters:

Substrate
Km (μM)
Citations
ethyl-2-methylacetoacetate
3100.0
[Habrych02]


Enzymatic reaction of: 2,5-diketo-D-gluconate reductase

Synonyms: 25DKGR-A

EC Number: 1.1.1.346

2-keto-L-gulonate + NADP+ <=> 2,5-didehydro-D-gluconate + NADPH + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the opposite direction.

In Pathways: ketogluconate metabolism

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International

Kinetic Parameters:

Substrate
Specific Activity (U/mg)
Citations
2,5-didehydro-D-gluconate
[Ko05]

pH(opt): 7.5 [Yum99]


Sequence Features

Feature Class Location Citations Comment
Active-Site 51
[UniProt10a]
UniProt: Proton donor; Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 107
[UniProt10a]
UniProt: Substrate; Non-Experimental Qualifier: by similarity;
Nucleotide-Phosphate-Binding-Region 187 -> 241
[UniProt10a]
UniProt: NADP; Non-Experimental Qualifier: by similarity;

History:
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.


References

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

GOA01: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA01a: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

Habrych02: Habrych M, Rodriguez S, Stewart JD (2002). "Purification and identification of an Escherichia coli beta-keto ester reductase as 2,5-diketo-D-gluconate reductase YqhE." Biotechnol Prog 18(2);257-61. PMID: 11934293

Jeudy06: Jeudy S, Monchois V, Maza C, Claverie JM, Abergel C (2006). "Crystal structure of Escherichia coli DkgA, a broad-specificity aldo-keto reductase." Proteins 62(1);302-7. PMID: 16284956

Ko05: Ko J, Kim I, Yoo S, Min B, Kim K, Park C (2005). "Conversion of methylglyoxal to acetol by Escherichia coli aldo-keto reductases." J Bacteriol 187(16);5782-9. PMID: 16077126

Lapthorn13: Lapthorn AJ, Zhu X, Ellis EM (2013). "The diversity of microbial aldo/keto reductases from Escherichia coli K12." Chem Biol Interact 202(1-3);168-77. PMID: 23103600

Lee13b: Lee C, Kim I, Park C (2013). "Glyoxal detoxification in Escherichia coli K-12 by NADPH dependent aldo-keto reductases." J Microbiol 51(4);527-30. PMID: 23990306

LopezCampistrou05: Lopez-Campistrous A, Semchuk P, Burke L, Palmer-Stone T, Brokx SJ, Broderick G, Bottorff D, Bolch S, Weiner JH, Ellison MJ (2005). "Localization, annotation, and comparison of the Escherichia coli K-12 proteome under two states of growth." Mol Cell Proteomics 4(8);1205-9. PMID: 15911532

Miller09: Miller EN, Jarboe LR, Yomano LP, York SW, Shanmugam KT, Ingram LO (2009). "Silencing of NADPH-dependent oxidoreductase genes (yqhD and dkgA) in furfural-resistant ethanologenic Escherichia coli." Appl Environ Microbiol 75(13);4315-23. PMID: 19429550

Miller10a: Miller EN, Turner PC, Jarboe LR, Ingram LO (2010). "Genetic changes that increase 5-hydroxymethyl furfural resistance in ethanol-producing Escherichia coli LY180." Biotechnol Lett 32(5);661-7. PMID: 20131081

Rodriguez14: Rodriguez GM, Atsumi S (2014). "Toward aldehyde and alkane production by removing aldehyde reductase activity in Escherichia coli." Metab Eng 25;227-37. PMID: 25108218

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

Yum99: Yum DY, Lee BY, Pan JG (1999). "Identification of the yqhE and yafB genes encoding two 2, 5-diketo-D-gluconate reductases in Escherichia coli." Appl Environ Microbiol 1999;65(8);3341-6. PMID: 10427017


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Sun Dec 21, 2014, biocyc14.