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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
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Escherichia coli K-12 substr. MG1655 Polypeptide: acetolactate synthase II, large subunit, C-ter fragment (pseudogene)



Gene: ilvG_2 Accession Numbers: EG10498 (EcoCyc), b3768, ECK3760

Synonyms: ilvG, IlvO

Regulation Summary Diagram: ?

Component of: acetohydroxybutanoate synthase / acetolactate synthase (summary available)

Summary:
IlvG is not expressed in the canonical, sequenced E. coli K-12 due to an internal frameshift mutation that effectively cuts it in half [Favre76, Gray81]. Mutations that remove a single nucleotide or add two nucleotides can revert a strain to allow wild-type production of IlvG [Lawther81, Lawther82]. Based on a similar example in S. typhimurium, it has been suggested that this disabling mutation in IlvG is specific to the lab isolate, and is not representative of natural E. coli strains [Burns95].

E. coli K-12 with the ilvG mutation undergo oscillating cycles of isoleucine starvation due to abberant regulation of isoleucine biosynthesis. This is alleviated by restoration of IlvG expression [Andersen01a].

ilvG expression increases during growth on acetate [Oh00a].

ptsN knockout phenotypes relating to nitrogen source utilization regulation was observed only in strains lacking functional ilvG [Reaves11].

For the first half of this disrupted protein, see acetolactate synthase II, large subunit, N-ter fragment (pseudogene).

Gene Citations: [Sameshima89, Parekh97, Driver85, Lawther87]

Map Position: [3,949,646 -> 3,950,227] (85.13 centisomes)
Length: 582 bp / 193 aa

Molecular Weight of Polypeptide: 21.373 kD (from nucleotide sequence)

pI: 5.1 [Daniels92]

Isozyme Sequence Similarity [Comment 1]:
acetohydroxy acid synthase I, large subunit: YES ,
IlvI: YES

Unification Links: CGSC:603 , EcoliWiki:b3768 , PortEco:ilvG_2 , RegulonDB:EG10498

Relationship Links: EcoGene:RELATED-TO:EG10498 , ModBase:RELATED-TO:P00892 , Swiss-Model:RELATED-TO:P00892 , UniProt:RELATED-TO:P00892

Gene-Reaction Schematic: ?

Genetic Regulation Schematic: ?

GO Terms:

Biological Process: GO:0008652 - cellular amino acid biosynthetic process Inferred by computational analysis [UniProtGOA11a]
GO:0009082 - branched-chain amino acid biosynthetic process Inferred by computational analysis [UniProtGOA11a, GOA01a]
GO:0009097 - isoleucine biosynthetic process Inferred by computational analysis [UniProtGOA12]
GO:0009099 - valine biosynthetic process Inferred by computational analysis [UniProtGOA12]
Molecular Function: GO:0000287 - magnesium ion binding Inferred by computational analysis [GOA01a]
GO:0003824 - catalytic activity Inferred by computational analysis [GOA01a]
GO:0003984 - acetolactate synthase activity Inferred by computational analysis [GOA01, GOA01a]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11a]
GO:0030976 - thiamine pyrophosphate binding Inferred by computational analysis [GOA01a]
GO:0046872 - metal ion binding Inferred by computational analysis [UniProtGOA11a]
GO:0050660 - flavin adenine dinucleotide binding Inferred by computational analysis [GOA01a]

Gene Class: Pseudo-Genes Interrupted-Genes

Essentiality data for ilvG_2 knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
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]

Credits:
Last-Curated ? 17-Oct-2013 by Kubo A , SRI International


Subunit of: acetohydroxybutanoate synthase / acetolactate synthase

Synonyms: AHAS, AHAS II, acetohydroxy acid synthase II, acetohydroxybutanoate synthase II, acetolactate synthase II

Subunit composition of acetohydroxybutanoate synthase / acetolactate synthase = [IlvG_1][IlvG_2][IlvM]
         acetolactate synthase II, large subunit, N-ter fragment (pseudogene) = IlvG_1 (extended summary available)
         acetolactate synthase II, large subunit, C-ter fragment (pseudogene) = IlvG_2 (extended summary available)

Summary:
Acetohydroxyacid synthase II (AHAS II) catalyzes the biosynthesis of α-aceto-α-hydroxybutyrate and α-acetolactate. It is not found in E. coli K-12 due to a mutation in ilvG.

AHAS II is a bifunctional enzyme that catalyzes the biosynthesis of α-aceto-α-hydroxybutyrate for the isoleucine pathway and of α-acetolactate for the valine pathway [Dailey86]. Both IlvG and IlvM are required for this activity, though the exact stoichiometry of the IlvM subunit is unclear [Hill97, Lu87]. The kinetics of AHAS II have been evaluated [Hill97].

AHAS II is not present in E. coli K-12. See the entry for acetolactate synthase II, large subunit, N-ter fragment (pseudogene) for more information.

Credits:
Last-Curated ? 24-Feb-2006 by Shearer A , SRI International


Enzymatic reaction of: acetohydroxybutanoate synthase

Synonyms: acetolactate pyruvate-lyase (carboxylating), acetohydroxy acid synthase

EC Number: 2.2.1.6

pyruvate + 2-oxobutanoate + H+ <=> (S)-2-aceto-2-hydroxybutanoate + CO2

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 direction shown.

Alternative Substrates for pyruvate: 2-oxobutanoate , 2-oxobutanoate

In Pathways: superpathway of leucine, valine, and isoleucine biosynthesis , superpathway of threonine metabolism , isoleucine biosynthesis I (from threonine)

Cofactors or Prosthetic Groups: thiamin diphosphate , FAD [Hill97], FAD [Hill97]

Inhibitors (Unknown Mechanism): L-leucine , L-valine


Enzymatic reaction of: acetolactate synthase

Synonyms: acetolactate pyruvate-lyase (carboxylating), acetohydroxy acid synthase

EC Number: 2.2.1.6

2 pyruvate + H+ <=> (S)-2-acetolactate + CO2

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

This reaction is reversible.

In Pathways: superpathway of leucine, valine, and isoleucine biosynthesis , valine biosynthesis

Cofactors or Prosthetic Groups: thiamin diphosphate , FAD [Hill97], FAD [Hill97]

Inhibitors (Unknown Mechanism): glyoxylate [Vinogradov05] , sulfometuron methyl [LaRossa84]


Sequence Features

Feature Class Location Citations Comment
Amino-Acid-Sites-That-Bind 47
[UniProt10]
UniProt: Thiamine pyrophosphate; Non-Experimental Qualifier: by similarity;
Amino-Acid-Sites-That-Bind 149
[UniProt10]
UniProt: FAD; Non-Experimental Qualifier: by similarity;


Gene Local Context (not to scale): ?

Transcription Units:

Notes:

History:
Ingrid Keseler on Mon Oct 16, 2006:
Gene start position adjusted according to Riley et al. (2006)
4/24/1998 (pkarp) Merged genes G7795/ilvG and EG10498/ilvG
1/26/1998 (pkarp) Merged genes G7796/ilvG_2 and EG10498/ilvG
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.


References

Andersen01a: Andersen DC, Swartz J, Ryll T, Lin N, Snedecor B (2001). "Metabolic oscillations in an E. coli fermentation." Biotechnol Bioeng 75(2);212-8. PMID: 11536144

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

Bairoch93: Bairoch A, Boeckmann B (1993). "The SWISS-PROT protein sequence data bank, recent developments." Nucleic Acids Res. 21:3093-3096. PMID: 8332529

Burns95: Burns DM, Burger MJ, Beacham IR (1995). "Silent genes in bacteria: the previously designated 'cryptic' ilvHI locus of 'Salmonella typhimurium LT2' is active in natural isolates." FEMS Microbiol Lett 131(2);167-72. PMID: 7557326

Dailey86: Dailey FE, Cronan JE (1986). "Acetohydroxy acid synthase I, a required enzyme for isoleucine and valine biosynthesis in Escherichia coli K-12 during growth on acetate as the sole carbon source." J Bacteriol 1986;165(2);453-60. PMID: 3511034

Daniels92: Daniels DL, Plunkett G, Burland V, Blattner FR (1992). "Analysis of the Escherichia coli genome: DNA sequence of the region from 84.5 to 86.5 minutes." Science 1992;257(5071);771-8. PMID: 1379743

Driver85: Driver RP, Lawther RP (1985). "Physical analysis of deletion mutations in the ilvGEDA operon of Escherichia coli K-12." J Bacteriol 162(2);598-606. PMID: 2985538

Favre76: Favre R, Wiater A, Puppo S, Iaccarino M (1976). "Expression of a valine-resistant acetolactate synthase activity mediated by the ilv O and ilv G genes of Escherichia coli K-12." Mol Gen Genet 143(3);243-52. PMID: 765758

GOA01: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

Gray81: Gray JE, Patin DW, Calhoun DH (1981). "Identification of the protein products of the rrnC, ilv, rho region of the Escherichia coli K-12 chromosome." Mol Gen Genet 183(3);428-36. PMID: 6460909

Hill97: Hill CM, Pang SS, Duggleby RG (1997). "Purification of Escherichia coli acetohydroxyacid synthase isoenzyme II and reconstitution of active enzyme from its individual pure subunits." Biochem J 327 ( Pt 3);891-8. PMID: 9581571

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

LaRossa84: LaRossa RA, Schloss JV (1984). "The sulfonylurea herbicide sulfometuron methyl is an extremely potent and selective inhibitor of acetolactate synthase in Salmonella typhimurium." J Biol Chem 1984;259(14);8753-7. PMID: 6378902

Lawther81: Lawther RP, Calhoun DH, Adams CW, Hauser CA, Gray J, Hatfield GW (1981). "Molecular basis of valine resistance in Escherichia coli K-12." Proc Natl Acad Sci U S A 78(2);922-5. PMID: 7015336

Lawther82: Lawther RP, Calhoun DH, Gray J, Adams CW, Hauser CA, Hatfield GW (1982). "DNA sequence fine-structure analysis of ilvG (IlvG+) mutations of Escherichia coli K-12." J Bacteriol 149(1);294-8. PMID: 7033211

Lawther87: Lawther RP, Wek RC, Lopes JM, Pereira R, Taillon BE, Hatfield GW (1987). "The complete nucleotide sequence of the ilvGMEDA operon of Escherichia coli K-12." Nucleic Acids Res 1987;15(5);2137-55. PMID: 3550695

Lu87: Lu MF, Umbarger HE (1987). "Effects of deletion and insertion mutations in the ilvM gene of Escherichia coli." J Bacteriol 169(2);600-4. PMID: 3027038

Oh00a: Oh MK, Liao JC (2000). "Gene expression profiling by DNA microarrays and metabolic fluxes in Escherichia coli." Biotechnol Prog 16(2);278-86. PMID: 10753455

Parekh97: Parekh BS, Hatfield GW (1997). "Growth rate-related regulation of the ilvGMEDA operon of Escherichia coli K-12 is a consequence of the polar frameshift mutation in the ilvG gene of this strain." J Bacteriol 1997;179(6);2086-8. PMID: 9068661

Reaves11: Reaves ML, Rabinowitz JD (2011). "Characteristic phenotypes associated with ptsN-null mutants in Escherichia coli K-12 are absent in strains with functional ilvG." J Bacteriol 193(18);4576-81. PMID: 21531803

Sameshima89: Sameshima JH, Wek RC, Hatfield GW (1989). "Overlapping transcription and termination of the convergent ilvA and ilvY genes of Escherichia coli." J Biol Chem 1989;264(2);1224-31. PMID: 2642900

UniProt10: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

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

UniProtGOA12: UniProt-GOA (2012). "Gene Ontology annotation based on UniPathway vocabulary mapping."

Vinogradov05: Vinogradov M, Kaplun A, Vyazmensky M, Engel S, Golbik R, Tittmann K, Uhlemann K, Meshalkina L, Barak Z, Hubner G, Chipman DM (2005). "Monitoring the acetohydroxy acid synthase reaction and related carboligations by circular dichroism spectroscopy." Anal Biochem 342(1);126-33. PMID: 15958189

Other References Related to Gene Regulation

Adams85: Adams CW, Rosenberg M, Hatfield GW (1985). "Analysis of in vivo RNA transcription products of the ilvGEDA attenuator region of Escherichia coli K12." J Biol Chem 1985;260(14);8538-44. PMID: 2409090

Pagel91: Pagel JM, Hatfield GW (1991). "Integration host factor-mediated expression of the ilvGMEDA operon of Escherichia coli." J Biol Chem 1991;266(3);1985-96. PMID: 1703160

Pagel92: Pagel JM, Winkelman JW, Adams CW, Hatfield GW (1992). "DNA topology-mediated regulation of transcription initiation from the tandem promoters of the ilvGMEDA operon of Escherichia coli." J Mol Biol 1992;224(4);919-35. PMID: 1569580

Parekh96: Parekh BS, Hatfield GW (1996). "Transcriptional activation by protein-induced DNA bending: evidence for a DNA structural transmission model." Proc Natl Acad Sci U S A 1996;93(3);1173-7. PMID: 8577735

Parekh96a: Parekh BS, Sheridan SD, Hatfield GW (1996). "Effects of integration host factor and DNA supercoiling on transcription from the ilvPG promoter of Escherichia coli." J Biol Chem 1996;271(34);20258-64. PMID: 8702758

Rhee96: Rhee KY, Parekh BS, Hatfield GW (1996). "Leucine-responsive regulatory protein-DNA interactions in the leader region of the ilvGMEDA operon of Escherichia coli." J Biol Chem 1996;271(43);26499-507. PMID: 8900118

Subrahmanyam80: Subrahmanyam CS, Noti JD, Umbarger HE (1980). "Regulation of ilvEDA expression occurs upstream of ilvG in Escherichia coli: additional evidence for an ilvGEDA operon." J Bacteriol 144(1);279-90. PMID: 6252193

Tsui88: Tsui P, Freundlich M (1988). "Integration host factor binds specifically to sites in the ilvGMEDA operon in Escherichia coli." J Mol Biol 203(3);817-20. PMID: 3145340


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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 18.5 on Sat Dec 20, 2014, BIOCYC14B.