Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store
Updated BioCyc iOS App now
available in iTunes store

MetaCyc Pathway: guanine and guanosine salvage II
Traceable author statement to experimental support

Enzyme View:

Pathway diagram: guanine and guanosine salvage II

This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Superclasses: BiosynthesisNucleosides and Nucleotides BiosynthesisPurine Nucleotide BiosynthesisPurine Nucleotide SalvageGuanine and Guanosine Salvage

Some taxa known to possess this pathway include : Lupinus luteus, Trypanosoma brucei brucei, Trypanosoma vivax

Expected Taxonomic Range: Bacteria , Eukaryota

Many organisms can synthesize guanosine nucleotides de novo. In that route GMP (GMP) is synthesized via IMP (IMP) and XMP (XMP) , which is converted to GMP by the action of GMP synthetase, an enzyme that can use either glutamine or ammonia as substrate (see superpathway of guanosine nucleotides de novo biosynthesis II). Note that the free base guanine or the ribonucleoside guanosine are not produced via the de novo pathway.

Many organisms also use salvage enzymes to obtain purine bases and nucleosides and convert them to the corresponding nucleotides. The pathway described here is used by both prokaryotic and eukaryotic organisms for this purpose. For example, all parasitic protozoa (e.g. Plasmodium , Toxoplasma , Leishmania , Trypanosoma) lack the ability to synthesize purine nucleotides de novoand use this salvage pathway to convert purine bases and nucleosides obtained from their hosts to the corresponding nucleotides [Ogbunude85, Davies83]. After their uptake by specific transporters [James80, deKoning00] the purine nucleosides are first hydrolyzed to ribose and a base by nucleoside hydrolases. The bases are then converted to the concomitant nucleotides by xanthine-guanine phosphoribosyltransferase, which utilizes 5-phospho-α-D-ribose 1-diphosphate to convert the free base to the mononucleotide GMP. Nucleoside hydrolases from parasites are attractive drug targets against parasitic protozoa since no such activity has been reported thus far in mammalian cells [Hammond84].

The pathway has also been described in green plants [Guranowski79].

Other routes from guanosine to GMP are described in guanine and guanosine salvage and guanine and guanosine salvage III.

Variants: guanine and guanosine salvage, guanine and guanosine salvage III, superpathway of guanine and guanosine salvage

Created 16-Sep-2010 by Caspi R, SRI International


Davies83: Davies MJ, Ross AM, Gutteridge WE (1983). "The enzymes of purine salvage in Trypanosoma cruzi, Trypanosoma brucei and Leishmania mexicana." Parasitology 87 (Pt 2);211-7. PMID: 6316234

deKoning00: de Koning HP, Watson CJ, Sutcliffe L, Jarvis SM (2000). "Differential regulation of nucleoside and nucleobase transporters in Crithidia fasciculata and Trypanosoma brucei brucei." Mol Biochem Parasitol 106(1);93-107. PMID: 10743614

Guranowski79: Guranowski, Andrzej, Barankiewicz, Jerzy (1979). "Purine salvage in cotyledons of germinating lupin seeds." FEBS Letters 104(1): 95-98.

Hammond84: Hammond DJ, Gutteridge WE (1984). "Purine and pyrimidine metabolism in the Trypanosomatidae." Mol Biochem Parasitol 13(3);243-61. PMID: 6396514

James80: James DM, Born GV (1980). "Uptake of purine bases and nucleosides in African trypanosomes." Parasitology 81(2);383-93. PMID: 7443300

Ogbunude85: Ogbunude PO, Ikediobi CO, Ukoha AI (1985). "Adenosine cycle in African trypanosomes." Ann Trop Med Parasitol 79(1);7-11. PMID: 3920982

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Allen93: Allen TE, Ullman B (1993). "Cloning and expression of the hypoxanthine-guanine phosphoribosyltransferase gene from Trypanosoma brucei." Nucleic Acids Res 21(23);5431-8. PMID: 8265360

Deo85: Deo SS, Tseng WC, Saini R, Coles RS, Athwal RS (1985). "Purification and characterization of Escherichia coli xanthine-guanine phosphoribosyltransferase produced by plasmid pSV2gpt." Biochim Biophys Acta 839(3);233-9. PMID: 3886014

Elshafei95: Elshafei AM, Abu-Shady MR, el-Beih FM, Mohamed LA (1995). "Mode and extent of degradation of adenosine and guanosine by extracts of Aspergillus terricola." Microbiol Res 150(3);291-5. PMID: 7551735

Free90: Free ML, Gordon RB, Keough DT, Beacham IR, Emmerson BT, de Jersey J (1990). "Expression of active human hypoxanthine-guanine phosphoribosyltransferase in Escherichia coli and characterisation of the recombinant enzyme." Biochim Biophys Acta 1087(2);205-11. PMID: 2223882

Guddat02: Guddat LW, Vos S, Martin JL, Keough DT, de Jersey J (2002). "Crystal structures of free, IMP-, and GMP-bound Escherichia coli hypoxanthine phosphoribosyltransferase." Protein Sci 11(7);1626-38. PMID: 12070315

Guranowski82: Guranowski, Andrzej (1982). "Purine catabolism in plants, purification and some properties of inosine nucleosidase from yellow lupin seeds." Plant Physiology 70:344-349.

Hirose84: Hirose, Fumiko, Ashihara, Hiroshi (1984). "Changes in the activity of enzymes involved in purine "salvage" and nucleic acid degrdation during the growth of Catharanthus roseus cells in suspension culture." Physiol. Plant. 60:532-538.

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Liu83: Liu SW, Milman G (1983). "Purification and characterization of Escherichia coli guanine-xanthine phosphoribosyltransferase produced by a high efficiency expression plasmid utilizing a lambda PL promoter and CI857 temperature-sensitive repressor." J Biol Chem 1983;258(12);7469-75. PMID: 6305942

Nussbaum81: Nussbaum RL, Caskey CT (1981). "Purification and characterization of hypoxanthine-guanine phosphoribosyltransferase from Saccharomyces cerevisiae." Biochemistry 20(16);4584-90. PMID: 6170313

Qian07a: Qian W, Liu X, Qin H, Wang D (2007). "Molecular and functional analysis of hypoxanthine-guanine phosphoribosyltransferase from Arabidopsis thaliana." New Phytol 175(3);448-61. PMID: 17635220

Schmidt79: Schmidt R, Wiegand H, Reichert U (1979). "Purification and characterization of the hypoxanthine-guanine phosphoribosyltransferase from Saccharomyces cerevisiae." Eur J Biochem 93(2);355-61. PMID: 371963

Versees01: Versees W, Decanniere K, Pelle R, Depoorter J, Brosens E, Parkin DW, Steyaert J (2001). "Structure and function of a novel purine specific nucleoside hydrolase from Trypanosoma vivax." J Mol Biol 307(5);1363-79. PMID: 11292348

Vos97: Vos S, de Jersey J, Martin JL (1997). "Crystal structure of Escherichia coli xanthine phosphoribosyltransferase." Biochemistry 36(14);4125-34. PMID: 9100006

Xu97: Xu Y, Eads J, Sacchettini JC, Grubmeyer C (1997). "Kinetic mechanism of human hypoxanthine-guanine phosphoribosyltransferase: rapid phosphoribosyl transfer chemistry." Biochemistry 36(12);3700-12. PMID: 9132023

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Sat Apr 30, 2016, biocyc13.