|Gene:||idnO||Accession Numbers: G7892 (MetaCyc), b4266, ECK4259|
Species: Escherichia coli K-12 substr. MG1655
5-Keto-D-gluconate 5-reductase catalyzes the reversible reduction of 5-ketogluconate to D-gluconate. This is the second reaction of the L-idonate catabolic pathway after uptake of L-idonate into the cell. The enzyme specifically reduces 5-ketogluconate using either NADH or NADPH. D-gluconate oxidation by the enzyme can only proceed with NAD as the coenzyme; NADP only results in low specific activity [Bausch98].
Based on sequence similarity, IdnO was predicted to be an acetoin dehydrogenase (diacetyl reductase) [Reed03].
Expression of the idnDOTR operon is catabolite repressed and induced by L-idonate or 5-ketogluconate [Bausch04].
IdnO: "idonate" [Bausch98]
|Map Position: [4,490,610 <- 4,491,374]|
Molecular Weight of Polypeptide: 27.563 kD (from nucleotide sequence)
Unification Links: ASAP:ABE-0013971 , EchoBASE:EB2429 , EcoGene:EG12540 , EcoliWiki:b4266 , Mint:MINT-1231433 , ModBase:P0A9P9 , OU-Microarray:b4266 , PortEco:idnO , PR:PRO_000022995 , Protein Model Portal:P0A9P9 , RefSeq:NP_418687 , RegulonDB:G7892 , SMR:P0A9P9 , String:511145.b4266 , UniProt:P0A9P9
Relationship Links: EcoO157Cyc:Homolog:Z1533 , EcoO157Cyc:Homolog:Z1533-MONOMER , InterPro:IN-FAMILY:IPR002198 , InterPro:IN-FAMILY:IPR002347 , InterPro:IN-FAMILY:IPR016040 , InterPro:IN-FAMILY:IPR020904 , Pfam:IN-FAMILY:PF00106 , Prints:IN-FAMILY:PR00080 , Prints:IN-FAMILY:PR00081 , Prosite:IN-FAMILY:PS00061
Instance reactions of [D-gluconate + NAD(P)+ ↔ 5-dehydro-D-gluconate + NAD(P)H + H+] (126.96.36.199):
|Biological Process:||GO:0046183 - L-idonate catabolic process
GO:0008152 - metabolic process [GOA01a]
GO:0019521 - D-gluconate metabolic process [UniProtGOA11a]
GO:0055114 - oxidation-reduction process [UniProtGOA11a]
|Molecular Function:||GO:0008874 - gluconate 5-dehydrogenase activity
[GOA01, Yum99, Bausch98]
GO:0016491 - oxidoreductase activity [UniProtGOA11a, GOA01a]
|Cellular Component:||GO:0005737 - cytoplasm
GO:0005829 - cytosol [DiazMejia09]
|MultiFun Terms:||metabolism → carbon utilization → carbon compounds|
Enzymatic reaction of: 5-keto-D-gluconate 5-reductase
Synonyms: gluconate 5-dehydrogenase, D-gluconate:NAD(P)+ 5-oxidoreductase, 5KDGR
EC Number: 188.8.131.52
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.
This reaction is reversible. [Bausch98]
Alternative Substrates [Comment 1]:
The specific activity of the enzyme in the 5-keto-D-gluconate 5-reductase direction is more than 10-fold higher than in the oxidation direction [Bausch98]. Although the enzyme can utilize both NADH and NADPH, it has three times the activity using NADH [Yum99].
pH(opt) (reverse direction): 8.0 [Yum99]
|Nucleotide-Phosphate-Binding-Region||13 -> 37|
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.
Bausch04: Bausch C, Ramsey M, Conway T (2004). "Transcriptional organization and regulation of the L-idonic acid pathway (GntII system) in Escherichia coli." J Bacteriol 186(5);1388-97. PMID: 14973046
Bausch98: Bausch C, Peekhaus N, Utz C, Blais T, Murray E, Lowary T, Conway T (1998). "Sequence analysis of the GntII (subsidiary) system for gluconate metabolism reveals a novel pathway for L-idonic acid catabolism in Escherichia coli." J Bacteriol 1998;180(14);3704-10. PMID: 9658018
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
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
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