Escherichia coli K-12 substr. MG1655 Enzyme: GMP reductase

Gene: guaC Accession Numbers: EG10422 (EcoCyc), b0104, ECK0104

Regulation Summary Diagram: ?

Regulation summary diagram for guaC

Subunit composition of GMP reductase = [GuaC]4

GMP reductase catalyzes the conversion of GMP to IMP by reductive deamination. This reaction is part of the purine salvage pathway and becomes essential when purine-requiring mutants are grown with guanine or xanthine as the sole sources of purine.

GMP reductase follows an ordered bi-bi kinetic mechanism [Martinelli11].

Expression of guaC is induced by guanine derivatives and repressed by adenine [Nijkamp67, Benson71, Kessler85]. GMP is thought to be the most probable inducer in vivo [Kessler85]. Expression is sensitive to cAMP levels, although not due to catabolite repression [Benson71]. Sequences in the predicted guaC promoter region indicate that expression may be regulated by the stringent response [Andrews88].

Locations: cytosol

Map Position: [113,444 -> 114,487] (2.45 centisomes, 9°)
Length: 1044 bp / 347 aa

Molecular Weight of Polypeptide: 37.384 kD (from nucleotide sequence), 36.0 kD (experimental) [Moffat85 ]

Molecular Weight of Multimer: 155.98 kD (experimental) [Martinelli11]

pI: 6.67

Unification Links: ASAP:ABE-0000362 , CGSC:655 , DIP:DIP-47861N , EchoBASE:EB0417 , EcoGene:EG10422 , EcoliWiki:b0104 , Mint:MINT-1311378 , ModBase:P60560 , OU-Microarray:b0104 , PortEco:guaC , PR:PRO_000022852 , Pride:P60560 , Protein Model Portal:P60560 , RefSeq:NP_414646 , RegulonDB:EG10422 , SMR:P60560 , String:511145.b0104 , Swiss-Model:P60560 , UniProt:P60560

Relationship Links: InterPro:IN-FAMILY:IPR001093 , InterPro:IN-FAMILY:IPR005993 , InterPro:IN-FAMILY:IPR013785 , InterPro:IN-FAMILY:IPR015875 , Pfam:IN-FAMILY:PF00478 , Prosite:IN-FAMILY:PS00487

In Paralogous Gene Group: 34 (2 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0015951 - purine ribonucleotide interconversion Inferred from experiment [Mager60]
GO:0006163 - purine nucleotide metabolic process Inferred by computational analysis [GOA06]
GO:0009117 - nucleotide metabolic process Inferred by computational analysis [GOA01]
GO:0055114 - oxidation-reduction process Inferred by computational analysis [UniProtGOA11, GOA01]
Molecular Function: GO:0003920 - GMP reductase activity Inferred from experiment Inferred by computational analysis [GOA06, GOA01a, GOA01, Martinelli11]
GO:0005515 - protein binding Inferred from experiment [Butland05]
GO:0042802 - identical protein binding Inferred from experiment [Martinelli11]
GO:0003824 - catalytic activity Inferred by computational analysis [GOA01]
GO:0016491 - oxidoreductase activity Inferred by computational analysis [UniProtGOA11, GOA01]
GO:0046872 - metal ion binding Inferred by computational analysis [UniProtGOA11]
Cellular Component: GO:0005829 - cytosol Inferred from experiment Inferred by computational analysis [DiazMejia09, Ishihama08, LopezCampistrou05]
GO:0005737 - cytoplasm Inferred by curator [Roberts88]
GO:1902560 - GMP reductase complex Inferred by computational analysis [GOA01a, GOA01]

MultiFun Terms: metabolism central intermediary metabolism nucleotide and nucleoside conversions

Essentiality data for guaC knockouts: ?

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]

Last-Curated ? 17-Feb-2011 by Keseler I , SRI International

Enzymatic reaction of: GMP reductase

Synonyms: guanosine 5'-monophosphate oxidoreductase, NADPH:guanosine-5'-phosphate oxidoreductase (deaminating)

EC Number:

GMP + NADPH + 2 H+ <=> ammonium + IMP + NADP+

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 irreversible in the direction shown. [Mager60]

Extensive studies on the kinetics of the enzymatic reaction have been performed [Martinelli11].

Inhibitors (Unknown Mechanism): ATP [Mager60, Comment 5]

Kinetic Parameters:

Km (μM)
kcat (sec-1)
kcat/Km (sec-1 μM-1)
[Mager60, BRENDA14]
5.5, 6.9
0.051, 0.041
[Martinelli11, BRENDA14]
14.7, 11.1
[Martinelli11, BRENDA14]

pH(opt): 7.5 [BRENDA14, Mager60], 7.5-8.2 [Mager60]

Sequence Features

Protein sequence of GuaC with features indicated

Feature Class Location Citations Comment
Nucleotide-Phosphate-Binding-Region 108 -> 131
UniProt: NADP; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 181
UniProt: Potassium; via carbonyl oxygen; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 183
UniProt: Potassium; via carbonyl oxygen; Non-Experimental Qualifier: by similarity;
Active-Site 186
UniProt: Thioimidate intermediate; Non-Experimental Qualifier: by similarity;
Nucleotide-Phosphate-Binding-Region 216 -> 239
UniProt: NADP; Non-Experimental Qualifier: by similarity;
Sequence-Conflict 233 -> 235
[Andrews88, Fujita94, UniProt10a]
UniProt: (in Ref. 1 and 2);
Acetylation-Modification 294

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


10/20/97 Gene b0104 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10422; confirmed by SwissProt match.


Andrews88: Andrews SC, Guest JR (1988). "Nucleotide sequence of the gene encoding the GMP reductase of Escherichia coli K12." Biochem J 1988;255(1);35-43. PMID: 2904262

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

Benson71: Benson CE, Brehmeyer BA, Gots JS (1971). "Requirement of cyclic AMP for induction of GMP reductase in Escherichia coli." Biochem Biophys Res Commun 43(5);1089-94. PMID: 4327955

BRENDA14: BRENDA team (2014). "Imported from BRENDA version existing on Aug 2014."

Butland05: Butland G, Peregrin-Alvarez JM, Li J, Yang W, Yang X, Canadien V, Starostine A, Richards D, Beattie B, Krogan N, Davey M, Parkinson J, Greenblatt J, Emili A (2005). "Interaction network containing conserved and essential protein complexes in Escherichia coli." Nature 433(7025);531-7. PMID: 15690043

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

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

Fujita94: Fujita N, Mori H, Yura T, Ishihama A (1994). "Systematic sequencing of the Escherichia coli genome: analysis of the 2.4-4.1 min (110,917-193,643 bp) region." Nucleic Acids Res 22(9);1637-9. PMID: 8202364

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

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.

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Ishihama08: Ishihama Y, Schmidt T, Rappsilber J, Mann M, Hartl FU, Kerner MJ, Frishman D (2008). "Protein abundance profiling of the Escherichia coli cytosol." BMC Genomics 9;102. PMID: 18304323

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

Kessler85: Kessler AI, Gots JS (1985). "Regulation of guaC expression in Escherichia coli." J Bacteriol 164(3);1288-93. PMID: 2999079

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

Mager60: Mager J, Magasanik B (1960). "Guanosine 5'-phosphate reductase and its role in the interconversion of purine nucleotides." J Biol Chem 235;1474-8. PMID: 14419794

Martinelli11: Martinelli LK, Ducati RG, Rosado LA, Breda A, Selbach BP, Santos DS, Basso LA (2011). "Recombinant Escherichia coli GMP reductase: kinetic, catalytic and chemical mechanisms, and thermodynamics of enzyme-ligand binary complex formation." Mol Biosyst. PMID: 21298178

Moffat85: Moffat KG, Mackinnon G (1985). "Cloning of the Escherichia coli K-12 guaC gene following its transposition into the RP4::Mu cointegrate." Gene 40(1);141-3. PMID: 3005121

Nijkamp67: Nijkamp HJ, De Haan PG (1967). "Genetic and biochemical studies of the guanosine 5'-monophosphate pathway in Escherichia coli." Biochim Biophys Acta 145(1);31-40. PMID: 4861262

Roberts88: Roberts RE, Lienhard CI, Gaines CG, Smith JM, Guest JR (1988). "Genetic and molecular characterization of the guaC-nadC-aroP region of Escherichia coli K-12." J Bacteriol 1988;170(1);463-7. PMID: 3275629

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

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-11 released on 2010-11-02 00:00:00." Database.

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

Yu08: Yu BJ, Kim JA, Moon JH, Ryu SE, Pan JG (2008). "The diversity of lysine-acetylated proteins in Escherichia coli." J Microbiol Biotechnol 18(9);1529-36. PMID: 18852508

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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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