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Escherichia coli K-12 substr. MG1655 Enzyme: adenine phosphoribosyltransferase



Gene: apt Accession Numbers: EG10051 (EcoCyc), b0469, ECK0463

Regulation Summary Diagram: ?

Subunit composition of adenine phosphoribosyltransferase = [Apt]2
         adenine phosphoribosyltransferase = Apt

Summary:
Adenine phosphoribosyltransferase is one of the purine salvage enzymes which play an important role in maintaining nucleotide pool balance in E. coli.

Enzyme activity is induced by growth on purines, amethopterin, and thymine and is higher in stationary phase cultures. The enzyme is subject to regulation by both repression (by uncyclized nucleoside 5'-phosphates) and end product inhibition [HochstadtOzer71]. Adenine phosphoribosyltransferase is cytoplasmic [Page78], but can be found associated with isolated membrane vesicles [HochstadtOzer71a].

Apt: "adenine phosphoribosyltransferase" [Kocharian76]

Gene Citations: [Hershey86]

Locations: cytosol

Map Position: [490,636 -> 491,187] (10.57 centisomes)
Length: 552 bp / 183 aa

Molecular Weight of Polypeptide: 19.859 kD (from nucleotide sequence)

Molecular Weight of Multimer: 40 kD (experimental) [HochstadtOzer71]

pI: 5.49

Unification Links: ASAP:ABE-0001628 , CGSC:1029 , DIP:DIP-36165N , EchoBASE:EB0049 , EcoGene:EG10051 , EcoliWiki:b0469 , ModBase:P69503 , OU-Microarray:b0469 , PortEco:apt , Pride:P69503 , Protein Model Portal:P69503 , RefSeq:NP_415002 , RegulonDB:EG10051 , SMR:P69503 , String:511145.b0469 , Swiss-Model:P69503 , UniProt:P69503

Relationship Links: InterPro:IN-FAMILY:IPR000836 , InterPro:IN-FAMILY:IPR005764 , PDB:Structure:2DY0 , Pfam:IN-FAMILY:PF00156 , Prosite:IN-FAMILY:PS00103

Gene-Reaction Schematic: ?

GO Terms:

Biological Process: GO:0006168 - adenine salvage Inferred from experiment Inferred by computational analysis [GOA01a, HochstadtOzer71]
GO:0006166 - purine ribonucleoside salvage Inferred by computational analysis [UniProtGOA11a]
GO:0009116 - nucleoside metabolic process Inferred by computational analysis [GOA01a]
GO:0044209 - AMP salvage Inferred by computational analysis [UniProtGOA12]
Molecular Function: GO:0000287 - magnesium ion binding Inferred from experiment [HochstadtOzer71]
GO:0003999 - adenine phosphoribosyltransferase activity Inferred from experiment Inferred by computational analysis [GOA01, GOA01a, HochstadtOzer71]
GO:0042802 - identical protein binding Inferred from experiment [HochstadtOzer71]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11a]
GO:0016757 - transferase activity, transferring glycosyl groups Inferred by computational analysis [UniProtGOA11a]
Cellular Component: GO:0005829 - cytosol Inferred from experiment Inferred by computational analysis [DiazMejia09, Ishihama08, LopezCampistrou05, Page78, Lasserre06]
GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, GOA01a]

MultiFun Terms: metabolism central intermediary metabolism nucleotide and nucleoside conversions

Essentiality data for apt knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 1]
M9 medium with 1% glycerol Yes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 2]
MOPS medium with 0.4% glucose Yes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 1]
Yes [Feist07, Comment 3]

Credits:
Curated 29-Sep-2010 by Keseler I , SRI International
Last-Curated ? 01-Dec-2011 by Fulcher C , SRI International


Enzymatic reaction of: adenine phosphoribosyltransferase

Synonyms: AMP pyrophosphorylase, transphosphoribosidase, APRT, AMP:pyrophosphate phospho-D-ribosyltransferase

EC Number: 2.4.2.7

5-phospho-α-D-ribose 1-diphosphate + adenine <=> AMP + diphosphate

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.

Alternative Substrates for adenine: 2,6-diaminopurine

In Pathways: adenine and adenosine salvage II

Summary:
Various 5' nucleotides inhibit enzymatic activity; ATP, dATP, ADP, dADP, AMP, dAMP, GTP, ITP, XTP, and UTP were tested. Inhibition is competitive with respect to PRPP. 3',5'-cAMP does not inhibit the enzyme [HochstadtOzer71].

Cofactors or Prosthetic Groups: Mg2+ [HochstadtOzer71]

Alternative Cofactors for Mg2+: Mn2+

Inhibitors (Competitive): Mg2+ [Hochstadt78, Comment 4] , AMP [HochstadtOzer71, Comment 5] , diphosphate [HochstadtOzer71, Comment 6] , a ribonucleoside triphosphate [HochstadtOzer71]

Inhibitors (Unknown Mechanism): Zn2+ [Hochstadt78] , Ba2+ [Hochstadt78] , Ca2+ [Hochstadt78]

Kinetic Parameters:

Substrate
Km (μM)
kcat (sec-1)
kcat/Km (sec-1 μM-1)
Citations
adenine
1.3
[Sin72, BRENDA14]
adenine
11.0
[HochstadtOzer71]
adenine
20.0
9.33
[Hochstadt78, BRENDA14]
5-phospho-α-D-ribose 1-diphosphate
10.0
[Sin72, BRENDA14]
5-phospho-α-D-ribose 1-diphosphate
125.0
[Hochstadt78, BRENDA14]
5-phospho-α-D-ribose 1-diphosphate
180.0
[HochstadtOzer71]

pH(opt): 7.8 [BRENDA14, Hochstadt78], 8 [HochstadtOzer71]


Gene Local Context (not to scale): ?

Transcription Unit:

Notes:

History:
10/20/97 Gene b0469 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10051; confirmed by SwissProt match.


References

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

BRENDA14: BRENDA team (2014). "Imported from BRENDA version existing on Aug 2014." http://www.brenda-enzymes.org.

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

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."

Hershey86: Hershey HV, Taylor MW (1986). "Nucleotide sequence and deduced amino acid sequence of Escherichia coli adenine phosphoribosyltransferase and comparison with other analogous enzymes." Gene 43(3);287-93. PMID: 3527873

Hochstadt78: Hochstadt J (1978). "Adenine phosphoribosyltransferase from Escherichia coli." Methods Enzymol 1978;51;558-67. PMID: 357906

HochstadtOzer71: Hochstadt-Ozer J, Stadtman ER (1971). "The regulation of purine utilization in bacteria. I. Purification of adenine phosphoribosyltransferase from Escherichia coli K12 and control of activity by nucleotides." J Biol Chem 246(17);5294-303. PMID: 4328693

HochstadtOzer71a: Hochstadt-Ozer J, Stadtman ER (1971). "The regulation of purine utilization in bacteria. II. Adenine phosphoribosyltransferase in isolated membrane preparations and its role in transport of adenine across the membrane." J Biol Chem 1971;246(17);5304-11. PMID: 4328694

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

Kocharian76: Kocharian ShM, sukhodolets VV (1976). "[Phenotypic manifestation of mutations involving resistance to 2,6-diaminopurine (apt) in the genome of purine auxotrophs of Escherichia coli K-12]." Genetika 12(7);100-8. PMID: 793927

Lasserre06: Lasserre JP, Beyne E, Pyndiah S, Lapaillerie D, Claverol S, Bonneu M (2006). "A complexomic study of Escherichia coli using two-dimensional blue native/SDS polyacrylamide gel electrophoresis." Electrophoresis 27(16);3306-21. PMID: 16858726

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

Page78: Page MG, Burton K (1978). "The location of purine phosphoribosyltransferase activities in Escherichia coli." Biochem J 1978;174(3);717-25. PMID: 365172

Sin72: Sin IL, Finch LR (1972). "Adenine phosphoribosyltransferase in Mycoplasma mycoides and Escherichia coli." J Bacteriol 112(1);439-44. PMID: 4562405

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

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."


Report Errors or Provide Feedback
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, biocyc12.