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Escherichia coli K-12 substr. MG1655 Transporter: guanine / hypoxanthine transporter GhxQ



Gene: ghxQ Accession Numbers: G7503 (EcoCyc), b4464, ECK2880

Synonyms: b2885 (obsolete), ygfR, b2884 (obsolete), ygfQ

Regulation Summary Diagram: ?

Summary:
Cloned and overexpressed GhxQ transports labelled guanine and hypoxanthine, but not adenine, xanthine, uric acid or uracil in E. coli K-12 [Papakostas13]. GhxQ is a member of the nucleobase:cation symporter 2 (NCS2) family of transporters [Saier09].

GhxQ has been predicted to be a xanthine, uracil permease by bioinformatic analysis [Xi00]. Expression of ghxQ was induced at acidic pH [Tucker02] and increased after puromycin challenge of a relA strain [Sabina03]. Expression of a genomic library clone containing ghxQ and fragments of its flanking genes resulted in reduced expression of a rybB-LacZ fusion [Thompson07].

ghxQ: guanine / hypoxanthine permease Q

Locations: inner membrane

Map Position: [3,025,143 -> 3,026,510] (65.2 centisomes)
Length: 1368 bp / 455 aa

Molecular Weight of Polypeptide: 46.758 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0174113 , EchoBASE:EB2879 , EcoGene:EG13067 , EcoliWiki:b4464 , OU-Microarray:b2884 , PortEco:ygfQ , Protein Model Portal:Q46817 , RefSeq:YP_026186 , RegulonDB:G7503 , String:511145.b4464 , UniProt:Q46817

Relationship Links: EcoO157Cyc:Homolog:Z4223 , EcoO157Cyc:Homolog:Z4223-MONOMER , EcoO157Cyc:Homolog:Z5153-MONOMER , InterPro:IN-FAMILY:IPR006043 , Panther:IN-FAMILY:PTHR11119 , Pfam:IN-FAMILY:PF00860 , Prosite:IN-FAMILY:PS01116

In Paralogous Gene Group: 467 (3 members)

Gene-Reaction Schematic: ?

GO Terms:

Biological Process: GO:0035344 - hypoxanthine transport Inferred from experiment [Papakostas13]
GO:0061489 - guanine import into cell Inferred from experiment [Papakostas13]
GO:0006810 - transport Inferred by computational analysis [UniProtGOA11a, Xi00]
GO:0055085 - transmembrane transport Inferred by computational analysis [GOA01a]
Molecular Function: GO:0015208 - guanine transmembrane transporter activity Inferred from experiment [Papakostas13]
GO:0005215 - transporter activity Inferred by computational analysis [GOA01a, Xi00]
Cellular Component: GO:0005886 - plasma membrane Inferred from experiment Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, DiazMejia09, Daley05]
GO:0005887 - integral component of plasma membrane Inferred by computational analysis [Daley05]
GO:0016020 - membrane Inferred by computational analysis [UniProtGOA11a, GOA01a]
GO:0016021 - integral component of membrane Inferred by computational analysis [UniProtGOA11a]

MultiFun Terms: transport Electrochemical potential driven transporters Porters (Uni-, Sym- and Antiporters)

Essentiality data for ghxQ 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]

Credits:
Curated 13-May-2008 by Johnson A , JCVI
Last-Curated ? 11-Dec-2013 by Mackie A , Macquarie University


Enzymatic reaction of: hypoxanthine transport

Inhibitors (Competitive): guanine (Kic = 3µM) [Papakostas13] , N1-methylguanine (Kic = 105µM) [Papakostas13] , thioguanine (Kic = 4µM) [Papakostas13] , azaguanine (Kic = 154µM) [Papakostas13] , mercaptopurine (Kic = 51µM) [Papakostas13]

Kinetic Parameters:

Substrate
Km (μM)
Vmax (µmol mg-1 min-1)
Citations
hypoxanthine
22.5
0.014
[Papakostas13]


Enzymatic reaction of: guanine transport (guanine / hypoxanthine transporter GhxQ)

Kinetic Parameters:

Substrate
Km (μM)
Vmax (µmol mg-1 min-1)
Citations
guanine
1.8
0.0034
[Papakostas13]


Sequence Features

Feature Class Location Citations Comment
Transmembrane-Region 35 -> 55
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 64 -> 84
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 87 -> 107
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 115 -> 135
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 151 -> 171
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 181 -> 201
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 210 -> 230
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 255 -> 275
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Nucleotide-Phosphate-Binding-Region 332 -> 339
[UniProt10a]
UniProt: ATP; Non-Experimental Qualifier: potential;
Transmembrane-Region 345 -> 365
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 366 -> 386
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 402 -> 422
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;
Transmembrane-Region 435 -> 455
[UniProt10a]
UniProt: Helical;; Non-Experimental Qualifier: potential;


Gene Local Context (not to scale): ?

Transcription Unit:

Notes:

History:
10/21/2004 (paley) Merged genes G7504/ygfR into G7503/ygfQ
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.
Peter D. Karp on Thu Jan 16, 2003:
Predicted gene function revised as a result of E. coli genome reannotation by Serres et al. [Serres01 ].
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.


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

Daley05: Daley DO, Rapp M, Granseth E, Melen K, Drew D, von Heijne G (2005). "Global topology analysis of the Escherichia coli inner membrane proteome." Science 308(5726);1321-3. PMID: 15919996

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

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

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

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

Papakostas13: Papakostas K, Botou M, Frillingos S (2013). "Functional identification of the hypoxanthine/guanine transporters YjcD and YgfQ and the adenine transporters PurP and YicO of Escherichia coli K-12." J Biol Chem 288(52);36827-40. PMID: 24214977

Sabina03: Sabina J, Dover N, Templeton LJ, Smulski DR, Soll D, LaRossa RA (2003). "Interfering with different steps of protein synthesis explored by transcriptional profiling of Escherichia coli K-12." J Bacteriol 185(20);6158-70. PMID: 14526028

Saier09: Saier MH, Yen MR, Noto K, Tamang DG, Elkan C (2009). "The Transporter Classification Database: recent advances." Nucleic Acids Res 37(Database issue);D274-8. PMID: 19022853

Serres01: Serres MH, Gopal S, Nahum LA, Liang P, Gaasterland T, Riley M (2001). "A functional update of the Escherichia coli K-12 genome." Genome Biol 2(9);RESEARCH0035. PMID: 11574054

Thompson07: Thompson KM, Rhodius VA, Gottesman S (2007). "{sigma}E Regulates and Is Regulated by a Small RNA in Escherichia coli." J Bacteriol 189(11);4243-56. PMID: 17416652

Tucker02: Tucker DL, Tucker N, Conway T (2002). "Gene expression profiling of the pH response in Escherichia coli." J Bacteriol 184(23);6551-8. PMID: 12426343

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 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."

Xi00: Xi H, Schneider BL, Reitzer L (2000). "Purine catabolism in Escherichia coli and function of xanthine dehydrogenase in purine salvage." J Bacteriol 182(19);5332-41. PMID: 10986234


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 Fri Nov 28, 2014, BIOCYC13B.