Record Information
Version2.0
Creation Date2012-05-31 10:21:39 -0600
Update Date2015-09-13 12:56:06 -0600
Secondary Accession Numbers
  • ECMDB00132
Identification
Name:Guanine
Description:Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA. Guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with conjugated double bonds. Being unsaturated, the bicyclic molecule is planar. The guanine nucleoside is called guanosine. High affinity binding of guanine nucleotides and the ability to hydrolyze bound GTP to GDP are characteristics of an extended family of intracellular proteins. Hypoxanthine-guanine phosphoribosyltransferase (HPRT, EC 2.4.2.8) is a purine salvage enzyme that catalyses the conversion of hypoxanthine and guanine to their respective mononucleotides. Peroxynitrite induces DNA base damage predominantly at guanine (G) and 8-oxoguanine (8-oxoG) nucleobases via oxidation reactions. G and 8-oxoG are the most reactive bases toward Peroxynitrite and possibly the major contributors to peroxynitrite-derived genotoxic and mutagenic lesions. The neutral G radical, reacts with NO2 to yield 8-nitroguanine and 5-nitro-4-guanidinohydantoin. (PMID: 16352449, 2435586)
Structure
Thumb
Synonyms:
  • 2-Amino-1,7-dihydro-6H-Purin-6-one
  • 2-Amino-1,9-dihydro-6H-purin-6-one
  • 2-Amino-1,9-dihydro-purin-6-one
  • 2-Amino-3,7-dihydro-6H-purin-6-one
  • 2-Amino-6-hydroxy-1H-purine
  • 2-Amino-6-hydroxypurine
  • 2-Amino-6-purinol
  • 2-Amino-Hypoxanthine
  • 2-Aminohypoxanthine
  • 6-Hydroxy-2-aminopurine
  • C.I. Natural White 1
  • CI Natural white 1
  • Dew Pearl
  • GUA
  • Guanin
  • Guanine
  • Guanine enol
  • GUN
  • Mearlmaid
  • Mearlmaid AA
  • Natural pearl essence
  • Natural White 1
  • Naturon
  • Pathocidin
  • Pearl Essence
  • Stella Polaris
Chemical Formula:C5H5N5O
Weight:Average: 151.1261
Monoisotopic: 151.049409807
InChI Key:UYTPUPDQBNUYGX-UHFFFAOYSA-N
InChI:InChI=1S/C5H5N5O/c6-5-9-3-2(4(11)10-5)7-1-8-3/h1H,(H4,6,7,8,9,10,11)
CAS number:73-40-5
IUPAC Name:2-amino-6,7-dihydro-3H-purin-6-one
Traditional IUPAC Name:2-aminohypoxanthine
SMILES:NC1=NC(=O)C2=C(N1)N=CN2
Chemical Taxonomy
DescriptionThis compound belongs to the class of chemical entities known as purines and purine derivatives. These are aromatic heterocyclic compounds containing a purine moiety, which is formed a pyrimidine-ring ring fused to an imidazole ring.
KingdomChemical entities
Super ClassOrganic compounds
ClassOrganoheterocyclic compounds
Sub ClassImidazopyrimidines
Direct ParentPurines and purine derivatives
Alternative Parents
Substituents
  • Purine
  • Hydroxypyrimidine
  • Pyrimidine
  • Heteroaromatic compound
  • Imidazole
  • Azole
  • Azacycle
  • Organic nitrogen compound
  • Organic oxygen compound
  • Organopnictogen compound
  • Hydrocarbon derivative
  • Organooxygen compound
  • Organonitrogen compound
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External Descriptors
Physical Properties
State:Solid
Charge:0
Melting point:360 °C
Experimental Properties:
PropertyValueSource
Water Solubility:2.08 mg/mL at 37 oC [YALKOWSKY,SH & DANNENFELSER,RM (1992)]PhysProp
LogP:-0.91 [HANSCH,C ET AL. (1995)]PhysProp
Predicted Properties
PropertyValueSource
Water Solubility2.31 mg/mLALOGPS
logP-0.92ALOGPS
logP-0.59ChemAxon
logS-1.8ALOGPS
pKa (Strongest Acidic)8.95ChemAxon
pKa (Strongest Basic)2.22ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count5ChemAxon
Hydrogen Donor Count3ChemAxon
Polar Surface Area96.16 Å2ChemAxon
Rotatable Bond Count0ChemAxon
Refractivity38.9 m3·mol-1ChemAxon
Polarizability13.34 Å3ChemAxon
Number of Rings2ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Biological Properties
Cellular Locations:Cytoplasm
Reactions:
SMPDB Pathways:
guanine and guanosine salvagePW002074 Pw002074Pw002074 greyscalePw002074 simple
preQ0 metabolismPW001893 Pw001893Pw001893 greyscalePw001893 simple
purine deoxyribonucleosides degradationPW002077 Pw002077Pw002077 greyscalePw002077 simple
purine ribonucleosides degradationPW002076 Pw002076Pw002076 greyscalePw002076 simple
KEGG Pathways:
EcoCyc Pathways:
  • guanine and guanosine salvage I PWY-6620
  • guanosine nucleotides degradation III PWY-6608
  • purine deoxyribonucleosides degradation PWY0-1297
  • purine ribonucleosides degradation to ribose-1-phosphate PWY0-1296
  • queuosine biosynthesis PWY-6700
Concentrations
ConcentrationStrainMediaGrowth StatusGrowth SystemTemperatureDetails
188± 0 uMK12 NCM3722Gutnick minimal complete medium (4.7 g/L KH2PO4; 13.5 g/L K2HPO4; 1 g/L K2SO4; 0.1 g/L MgSO4-7H2O; 10 mM NH4Cl) with 4 g/L glucoseMid-Log PhaseShake flask and filter culture37 oCPMID: 19561621
3± 0 uMK12 NCM3722Gutnick minimal complete medium (4.7 g/L KH2PO4; 13.5 g/L K2HPO4; 1 g/L K2SO4; 0.1 g/L MgSO4-7H2O; 10 mM NH4Cl) with 4 g/L glycerolMid-Log PhaseShake flask and filter culture37 oCPMID: 19561621
3± 0 uMK12 NCM3722Gutnick minimal complete medium (4.7 g/L KH2PO4; 13.5 g/L K2HPO4; 1 g/L K2SO4; 0.1 g/L MgSO4-7H2O; 10 mM NH4Cl) with 4 g/L acetateMid-Log PhaseShake flask and filter culture37 oCPMID: 19561621
65± 0 uMBW2511348 mM Na2HPO4, 22 mM KH2PO4, 10 mM NaCl, 45 mM (NH4)2SO4, supplemented with 1 mM MgSO4, 1 mg/l thiamine·HCl, 5.6 mg/l CaCl2, 8 mg/l FeCl3, 1 mg/l MnCl2·4H2O, 1.7 mg/l ZnCl2, 0.43 mg/l CuCl2·2H2O, 0.6 mg/l CoCl2·2H2O and 0.6 mg/l Na2MoO4·2H2O. 4 g/L GlucoStationary Phase, glucose limitedBioreactor, pH controlled, O2 and CO2 controlled, dilution rate: 0.2/h37 oCPMID: 17379776
Find out more about how we convert literature concentrations.
Spectra
Spectra:
Spectrum TypeDescriptionSplash Key
GC-MSGC-MS Spectrum - GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies)splash10-0udi-1938000000-e15e09f2007f35659bb9View in MoNA
GC-MSGC-MS Spectrum - GC-MS (3 TMS)splash10-0udi-3739000000-66a080b08ba9b9f82e20View in MoNA
GC-MSGC-MS Spectrum - GC-MSsplash10-0ff0-5900000000-f103c75addeafe7ac6f0View in MoNA
GC-MSGC-MS Spectrum - EI-Bsplash10-0udi-5900000000-0a63148e3a8dc8d026dfView in MoNA
GC-MSGC-MS Spectrum - GC-EI-TOFsplash10-0udi-1938000000-e15e09f2007f35659bb9View in MoNA
GC-MSGC-MS Spectrum - GC-MSsplash10-0udi-3739000000-66a080b08ba9b9f82e20View in MoNA
GC-MSGC-MS Spectrum - GC-EI-TOFsplash10-0udi-2928000000-073bf70794fe99ce737fView in MoNA
GC-MSGC-MS Spectrum - GC-EI-TOFsplash10-000t-2790000000-77e6b5b71c9ff6ad2b23View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-0udi-0901000000-2864e73c83444d566e9aView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-0a4i-2900000000-4229d3d01623054b4cebView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-000i-0900000000-d5ae84fefadd84f988b4View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-001i-0900000000-7d48b2e8db6967e98407View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-0uxr-0900000000-67a7784963ec75cecaa0View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-00di-9000000000-4569516f23d8a712b434View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-001i-0900000000-d928cac1226f19b8edc3View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Positivesplash10-0udi-0900000000-34059351f2cbd94a8accView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Negativesplash10-0udj-0903100000-deb9c022884d7c98782eView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Negativesplash10-001i-0900000000-45d9db80ce4657ef1773View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Negativesplash10-004i-1900000000-86b7ee5755cbb8236f5bView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT (LTQ Orbitrap XL, Thermo Scientfic) , Negativesplash10-0udi-0900000000-ba534850b64f39d81fa0View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF (UPLC Q-Tof Premier, Waters) , Positivesplash10-0udi-0900000000-422f992621ab9626d1b2View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF (UPLC Q-Tof Premier, Waters) , Negativesplash10-0f89-0900000000-64e388178db73f06cb20View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , negativesplash10-0udi-0900000000-f0a95c55947ca990359cView in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , negativesplash10-001i-0900000000-45d9db80ce4657ef1773View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-ITFT , negativesplash10-0udi-0900000000-ba534850b64f39d81fa0View in MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , negativesplash10-0f89-0900000000-64e388178db73f06cb20View in MoNA
LC-MS/MSLC-MS/MS Spectrum - , negativesplash10-0udi-0900000000-c2e1c1e8841cc741dac1View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0udi-0900000000-e74c005384d71f4787e5View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0udi-0900000000-de4a4c4479ea93d742b5View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0a5i-9800000000-da506476184e5c2313a4View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0udi-0900000000-03d17084c3cb072c0237View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0udi-2900000000-c372e3ba919cba4f561fView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-00kf-9200000000-8ac435f998deda6437e1View in MoNA
MSMass Spectrum (Electron Ionization)splash10-0udi-8900000000-699c510cfaf838ab1922View in MoNA
1D NMR1H NMR SpectrumNot Available
1D NMR1H NMR SpectrumNot Available
1D NMR13C NMR SpectrumNot Available
2D NMR[1H,1H] 2D NMR SpectrumNot Available
2D NMR[1H,13C] 2D NMR SpectrumNot Available
References
References:
  • Allgayer H, Kolb M, Stuber V, Kruis W: Effects of bile acids on base hydroxylation in a model of human colonic mucosal DNA. Cancer Detect Prev. 2002;26(1):85-9. Pubmed: 12088208
  • Bennett, B. D., Kimball, E. H., Gao, M., Osterhout, R., Van Dien, S. J., Rabinowitz, J. D. (2009). "Absolute metabolite concentrations and implied enzyme active site occupancy in Escherichia coli." Nat Chem Biol 5:593-599. Pubmed: 19561621
  • Boulias C, Moscarello MA: Guanine nucleotides stimulate hydrolysis of phosphatidyl inositol bis phosphate in human myelin membranes. Biochem Biophys Res Commun. 1989 Jul 14;162(1):282-7. Pubmed: 2546548
  • Castro-Gago M, Cid E, Trabazo S, Pavon P, Camina F, Rodriguez-Segade S, Einis Punal J, Rodriguez-Nunez A: Cerebrospinal fluid purine metabolites and pyrimidine bases after brief febrile convulsions. Epilepsia. 1995 May;36(5):471-4. Pubmed: 7614924
  • Fain JN, Wallace MA, Wojcikiewicz RJ: Evidence for involvement of guanine nucleotide-binding regulatory proteins in the activation of phospholipases by hormones. FASEB J. 1988 Jul;2(10):2569-74. Pubmed: 2838362
  • Groopman JD, Zhu JQ, Donahue PR, Pikul A, Zhang LS, Chen JS, Wogan GN: Molecular dosimetry of urinary aflatoxin-DNA adducts in people living in Guangxi Autonomous Region, People's Republic of China. Cancer Res. 1992 Jan 1;52(1):45-52. Pubmed: 1727385
  • Harkness RA: Hypoxanthine, xanthine and uridine in body fluids, indicators of ATP depletion. J Chromatogr. 1988 Jul 29;429:255-78. Pubmed: 3062020
  • Ishii, N., Nakahigashi, K., Baba, T., Robert, M., Soga, T., Kanai, A., Hirasawa, T., Naba, M., Hirai, K., Hoque, A., Ho, P. Y., Kakazu, Y., Sugawara, K., Igarashi, S., Harada, S., Masuda, T., Sugiyama, N., Togashi, T., Hasegawa, M., Takai, Y., Yugi, K., Arakawa, K., Iwata, N., Toya, Y., Nakayama, Y., Nishioka, T., Shimizu, K., Mori, H., Tomita, M. (2007). "Multiple high-throughput analyses monitor the response of E. coli to perturbations." Science 316:593-597. Pubmed: 17379776
  • Kanehisa, M., Goto, S., Sato, Y., Furumichi, M., Tanabe, M. (2012). "KEGG for integration and interpretation of large-scale molecular data sets." Nucleic Acids Res 40:D109-D114. Pubmed: 22080510
  • Keseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590. Pubmed: 21097882
  • Liu Z, Li T, Wang E: Simultaneous determination of guanine, uric acid, hypoxanthine and xanthine in human plasma by reversed-phase high-performance liquid chromatography with amperometric detection. Analyst. 1995 Aug;120(8):2181-4. Pubmed: 7677251
  • Niles, J. C., Wishnok, J. S., Tannenbaum, S. R. (2006). "Peroxynitrite-induced oxidation and nitration products of guanine and 8-oxoguanine: structures and mechanisms of product formation." Nitric Oxide 14:109-121. Pubmed: 16352449
  • Ohdoi C, Nyhan WL, Kuhara T: Chemical diagnosis of Lesch-Nyhan syndrome using gas chromatography-mass spectrometry detection. J Chromatogr B Analyt Technol Biomed Life Sci. 2003 Jul 15;792(1):123-30. Pubmed: 12829005
  • Parkinson SJ, Waldman SA: An intracellular adenine nucleotide binding site inhibits guanyly cyclase C by a guanine nucleotide-dependent mechanism. Biochemistry. 1996 Mar 12;35(10):3213-21. Pubmed: 8605156
  • Rodriguez-Nunez A, Camina F, Lojo S, Rodriguez-Segade S, Castro-Gago M: Concentrations of nucleotides, nucleosides, purine bases and urate in cerebrospinal fluid of children with meningitis. Acta Paediatr. 1993 Oct;82(10):849-52. Pubmed: 8241644
  • Russo TA, Jodush ST, Brown JJ, Johnson JR: Identification of two previously unrecognized genes (guaA and argC) important for uropathogenesis. Mol Microbiol. 1996 Oct;22(2):217-29. Pubmed: 8930907
  • Schei MA, Hessen JO, Lund E: House-dust mites and mattresses. Allergy. 2002 Jun;57(6):538-42. Pubmed: 12028120
  • Sculley DG, Dawson PA, Emmerson BT, Gordon RB: A review of the molecular basis of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency. Hum Genet. 1992 Nov;90(3):195-207. Pubmed: 1487231
  • Shioya M, Wakabayashi K, Yamashita K, Nagao M, Sugimura T: Formation of 8-hydroxydeoxyguanosine in DNA treated with fecapentaene-12 and -14. Mutat Res. 1989 Mar;225(3):91-4. Pubmed: 2927433
  • Spiegel AM: Signal transduction by guanine nucleotide binding proteins. Mol Cell Endocrinol. 1987 Jan;49(1):1-16. Pubmed: 2435586
  • Sreekumar A, Poisson LM, Rajendiran TM, Khan AP, Cao Q, Yu J, Laxman B, Mehra R, Lonigro RJ, Li Y, Nyati MK, Ahsan A, Kalyana-Sundaram S, Han B, Cao X, Byun J, Omenn GS, Ghosh D, Pennathur S, Alexander DC, Berger A, Shuster JR, Wei JT, Varambally S, Beecher C, Chinnaiyan AM: Metabolomic profiles delineate potential role for sarcosine in prostate cancer progression. Nature. 2009 Feb 12;457(7231):910-4. Pubmed: 19212411
  • Steyn LM, Harley EH: Intracellular activity of HPRT Cape Town: purine uptake and growth of cultured cells in selective media. J Inherit Metab Dis. 1985;8(4):198-203. Pubmed: 3939543
  • van der Werf, M. J., Overkamp, K. M., Muilwijk, B., Coulier, L., Hankemeier, T. (2007). "Microbial metabolomics: toward a platform with full metabolome coverage." Anal Biochem 370:17-25. Pubmed: 17765195
  • Weimann A, Belling D, Poulsen HE: Quantification of 8-oxo-guanine and guanine as the nucleobase, nucleoside and deoxynucleoside forms in human urine by high-performance liquid chromatography-electrospray tandem mass spectrometry. Nucleic Acids Res. 2002 Jan 15;30(2):E7. Pubmed: 11788733
  • Winder, C. L., Dunn, W. B., Schuler, S., Broadhurst, D., Jarvis, R., Stephens, G. M., Goodacre, R. (2008). "Global metabolic profiling of Escherichia coli cultures: an evaluation of methods for quenching and extraction of intracellular metabolites." Anal Chem 80:2939-2948. Pubmed: 18331064
  • Yafe A, Etzioni S, Weisman-Shomer P, Fry M: Formation and properties of hairpin and tetraplex structures of guanine-rich regulatory sequences of muscle-specific genes. Nucleic Acids Res. 2005 May 20;33(9):2887-900. Print 2005. Pubmed: 15908587
Synthesis Reference:Xiao, Xuhua; Ma, Weiyong. One-pot synthesis of guanine. Faming Zhuanli Shenqing Gongkai Shuomingshu (2007), 10pp.
Material Safety Data Sheet (MSDS)Download (PDF)
External Links:
ResourceLink
CHEBI ID16235
HMDB IDHMDB00132
Pubchem Compound ID764
Kegg IDC00242
ChemSpider ID744
WikipediaGuanine
BioCyc IDGUANINE
EcoCyc IDGUANINE
Ligand ExpoGUN

Enzymes

General function:
Involved in queuine tRNA-ribosyltransferase activity
Specific function:
Exchanges the guanine residue with 7-aminomethyl-7- deazaguanine in tRNAs with GU(N) anticodons (tRNA-Asp, -Asn, -His and -Tyr). After this exchange, a cyclopentendiol moiety is attached to the 7-aminomethyl group of 7-deazaguanine, resulting in the hypermodified nucleoside queuosine (Q) (7-(((4,5-cis- dihydroxy-2-cyclopenten-1-yl)amino)methyl)-7-deazaguanosine)
Gene Name:
tgt
Uniprot ID:
P0A847
Molecular weight:
42593
Reactions
[tRNA]-guanine + queuine = [tRNA]-queuine + guanine.
[tRNA]-guanine + 7-aminomethyl-7-carbaguanine = [tRNA]-7-aminomethyl-7-carbaguanine + guanine.
General function:
Involved in hypoxanthine phosphoribosyltransferase activity
Specific function:
This enzyme acts exclusively on hypoxanthine; it does not act on guanine
Gene Name:
hpt
Uniprot ID:
P0A9M2
Molecular weight:
20115
Reactions
IMP + diphosphate = hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate.
General function:
Involved in nucleoside metabolic process
Specific function:
Acts on guanine, xanthine and to a lesser extent hypoxanthine
Gene Name:
gpt
Uniprot ID:
P0A9M5
Molecular weight:
16971
Reactions
XMP + diphosphate = 5-phospho-alpha-D-ribose 1-diphosphate + xanthine.
General function:
Involved in purine-nucleoside phosphorylase activity
Specific function:
Cleavage of guanosine or inosine to respective bases and sugar-1-phosphate molecules
Gene Name:
deoD
Uniprot ID:
P0ABP8
Molecular weight:
25950
Reactions
Purine nucleoside + phosphate = purine + alpha-D-ribose 1-phosphate.
General function:
Involved in hydrolase activity, hydrolyzing N-glycosyl compounds
Specific function:
Hydrolyzes cytidine or uridine to ribose and cytosine or uracil, respectively. Has a clear preference for cytidine over uridine. Strictly specific for ribonucleosides. Has a low but significant activity for the purine nucleoside xanthosine
Gene Name:
rihB
Uniprot ID:
P33022
Molecular weight:
33748
Reactions
A pyrimidine nucleoside + H(2)O = D-ribose + a pyrimidine base.
General function:
Involved in adenine phosphoribosyltransferase activity
Specific function:
Catalyzes a salvage reaction resulting in the formation of AMP, that is energically less costly than de novo synthesis
Gene Name:
apt
Uniprot ID:
P69503
Molecular weight:
19859
Reactions
AMP + diphosphate = adenine + 5-phospho-alpha-D-ribose 1-diphosphate.
General function:
Involved in hydrolase activity
Specific function:
Catalyzes the hydrolytic deamination of guanine, producing xanthine and ammonia
Gene Name:
guaD
Uniprot ID:
P76641
Molecular weight:
50244
Reactions
Guanine + H(2)O = xanthine + NH(3).
General function:
Involved in purine-nucleoside phosphorylase activity
Specific function:
The nucleoside phosphorylases catalyze the phosphorolytic breakdown of the N-glycosidic bond in the nucleoside molecule, with the formation of the corresponding free bases and pentose-1-phosphate. This protein can degrade all purine nucleosides except adenosine and deoxyadenosine
Gene Name:
xapA
Uniprot ID:
P45563
Molecular weight:
29834

Transporters

General function:
Involved in transporter activity
Specific function:
Specific, proton motive force-dependent high-affinity transporter for xanthine
Gene Name:
xanP
Uniprot ID:
P0AGM9
Molecular weight:
48868
General function:
Involved in nucleoside transmembrane transporter activity
Specific function:
Constitutes the receptor for colicin K and phage T6, and functions as substrate-specific channel for nucleosides and deoxynucleosides
Gene Name:
tsx
Uniprot ID:
P0A927
Molecular weight:
33589