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.
Synonyms: adenosine nucleotides salvage III
|Superclasses:||Biosynthesis → Nucleosides and Nucleotides Biosynthesis → Purine Nucleotide Biosynthesis → Purine Nucleotide Salvage → Adenine and Adenosine Salvage|
Adenosine nucleotides can be synthesized de novo. In that route AMP (AMP) is synthesized via IMP (IMP) and adenylo-succinate , which is converted to AMP by the action of adenylosuccinate lyase (see superpathway of adenosine nucleotides de novo biosynthesis II). Note that the free base adenine or the ribonucleoside adenosine are not produced via the de novo pathway.
Many organisms can also recycle adenosine nucleotides by a combination of degradation and salvage pathways. The degradation pathways are responsible for the conversion of the nucleotides to the nucleoside ( adenosine) and free base form ( adenine), and further degradation to compounds that can be catabolized to basic building blocks (for example, see adenosine nucleotides degradation II).
The distinction between nucleoside degradation and recycling is not always straight forward. This pathway shares several steps with the pathway adenosine nucleotides degradation II. However, this salvage pathway starts with adenine (which is often transported into the organism) and ends with IMP, leading to biosynthesis of nucleotides, while the degradation pathway starts with the nucleotide form ( AMP) and ends with urate, which in most organisms is degraded further.
A key enzyme in this pathway is adenosine deaminase, which converts adenosine to inosine. This has been shown to be the main form of adenosine degradation by the fungi Aspergillus terricola [Elshafei95] and Penicillium palitans [Elshafei05].
Unification Links: EcoCyc:PWY-6609
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
Balendiran99: Balendiran GK, Molina JA, Xu Y, Torres-Martinez J, Stevens R, Focia PJ, Eakin AE, Sacchettini JC, Craig SP (1999). "Ternary complex structure of human HGPRTase, PRPP, Mg2+, and the inhibitor HPP reveals the involvement of the flexible loop in substrate binding." Protein Sci 8(5);1023-31. PMID: 10338013
Bennett03: Bennett EM, Li C, Allan PW, Parker WB, Ealick SE (2003). "Structural basis for substrate specificity of Escherichia coli purine nucleoside phosphorylase." J Biol Chem 278(47);47110-8. PMID: 12937174
Bennett03a: Bennett EM, Anand R, Allan PW, Hassan AE, Hong JS, Levasseur DN, McPherson DT, Parker WB, Secrist JA, Sorscher EJ, Townes TM, Waud WR, Ealick SE (2003). "Designer gene therapy using an Escherichia coli purine nucleoside phosphorylase/prodrug system." Chem Biol 10(12);1173-81. PMID: 14700625
Bertosa14: Bertosa B, Mikleusevic G, Wielgus-Kutrowska B, Narczyk M, Hajnic M, Lescic Asler I, Tomic S, Luic M, Bzowska A (2014). "Homooligomerization is needed for stability: a molecular modelling and solution study of Escherichia coli purine nucleoside phosphorylase." FEBS J 281(7);1860-71. PMID: 24785777
Bezirdzhian86: Bezirdzhian KhO, Kocharian ShM, Akopian ZhI (1986). "[Isolation of the hexameric form of purine nucleoside phosphorylase from E. coli. Comparative study of trimeric and hexameric forms of the enzyme]." Biokhimiia 1986;51(7);1085-92. PMID: 3089333
Bezirdzhian87: Bezirdzhian KhO, Kocharian ShM, Akopian ZhI (1987). "[Hexamere purine nucleoside phosphorylase from Escherichia coli K-12. Kinetic analysis and mechanism of reaction]." Biokhimiia 52(11);1770-6. PMID: 3125860
Bezirdzhian87a: Bezirdzhian KhO, Kocharian ShM, Akopian ZhI (1987). "[Hexameric purine nucleoside phosphorylase II from Escherichia coli K-12. Physico-chemical and catalytic properties and stabilization with substrates]." Biokhimiia 1987;52(10);1624-31. PMID: 3122852
Bonthron85: Bonthron DT, Markham AF, Ginsburg D, Orkin SH (1985). "Identification of a point mutation in the adenosine deaminase gene responsible for immunodeficiency." J Clin Invest 76(2);894-7. PMID: 3839802
Buxton75: Buxton RS (1975). "Genetic analysis of thymidine-resistant and low-thymine-requiring mutants of Escherichia coli K-12 induced by bacteriophage Mu-1." J Bacteriol 121(2);475-84. PMID: 1089630
Buxton80: Buxton RS, Hammer-Jespersen K, Valentin-Hansen P (1980). "A second purine nucleoside phosphorylase in Escherichia coli K-12. I. Xanthosine phosphorylase regulatory mutants isolated as secondary-site revertants of a deoD mutant." Mol Gen Genet 179(2);331-40. PMID: 7007808
Bzowska88: Bzowska A, Kulikowska E, Darzynkiewicz E, Shugar D (1988). "Purine nucleoside phosphorylase. Structure-activity relationships for substrate and inhibitor properties of N-1-, N-7-, and C-8-substituted analogues; differentiation of mammalian and bacterial enzymes with N-1-methylinosine and guanosine." J Biol Chem 263(19);9212-7. PMID: 3132457
Bzowska92: Bzowska A, Kulikowska E, Shugar D (1992). "Formycins A and B and some analogues: selective inhibitors of bacterial (Escherichia coli) purine nucleoside phosphorylase." Biochim Biophys Acta 1120(3);239-47. PMID: 1576149
Chang91: Chang ZY, Nygaard P, Chinault AC, Kellems RE (1991). "Deduced amino acid sequence of Escherichia coli adenosine deaminase reveals evolutionarily conserved amino acid residues: implications for catalytic function." Biochemistry 30(8);2273-80. PMID: 1998686
Daddona84: Daddona PE, Shewach DS, Kelley WN, Argos P, Markham AF, Orkin SH (1984). "Human adenosine deaminase. cDNA and complete primary amino acid sequence." J Biol Chem 259(19);12101-6. PMID: 6090454
Dandanell05: Dandanell G, Szczepanowski RH, Kierdaszuk B, Shugar D, Bochtler M (2005). "Escherichia coli purine nucleoside phosphorylase II, the product of the xapA gene." J Mol Biol 348(1);113-25. PMID: 15808857
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
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