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: purine salvage, salvage pathway of adenosine nucleosides, adenosine nucleosides salvage I
|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 enzyme purine phosphorylase (DeoD) (EC 126.96.36.199) cleaves adenosine to adenine and α-D-ribose-1-phosphate, while a second enzyme, such as adenine phosphoribosyltransferase, can utilize 5-phospho-α-D-ribose 1-diphosphate to convert the free base to the mononucleotide AMP.
Either of these routes enables the organism to salvage the degradation products of adenosine nucleotides, and recycle them back to nucleotide form.
Superpathways: superpathway of purine nucleotide salvage
Alfonzo97: Alfonzo JD, Sahota A, Taylor MW (1997). "Purification and characterization of adenine phosphoribosyltransferase from Saccharomyces cerevisiae." Biochim Biophys Acta 1341(2);173-82. PMID: 9357956
Allen02: Allen M, Qin W, Moreau F, Moffatt B (2002). "Adenine phosphoribosyltransferase isoforms of Arabidopsis and their potential contributions to adenine and cytokinin metabolism." Physiol Plant 115(1);56-68. PMID: 12010467
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
Ealick90: Ealick SE, Rule SA, Carter DC, Greenhough TJ, Babu YS, Cook WJ, Habash J, Helliwell JR, Stoeckler JD, Parks RE (1990). "Three-dimensional structure of human erythrocytic purine nucleoside phosphorylase at 3.2 A resolution." J Biol Chem 265(3);1812-20. PMID: 2104852
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
Jensen75: Jensen KF, Nygaard P (1975). "Purine nucleoside phosphorylase from Escherichia coli and Salmonella typhimurium. Purification and some properties." Eur J Biochem 1975;51(1);253-65. PMID: 235429
Lewis79: Lewis AS, Lowy BA (1979). "Human erythrocyte purine nucleoside phosphorylase: molecular weight and physical properties. A Theorell-Chance catalytic mechanism." J Biol Chem 254(19);9927-32. PMID: 114517
Radabaugh02: Radabaugh TR, Sampayo-Reyes A, Zakharyan RA, Aposhian HV (2002). "Arsenate reductase II. Purine nucleoside phosphorylase in the presence of dihydrolipoic acid is a route for reduction of arsenate to arsenite in mammalian systems." Chem Res Toxicol 15(5);692-8. PMID: 12018991
Silva03: Silva RG, Carvalho LP, Oliveira JS, Pinto CA, Mendes MA, Palma MS, Basso LA, Santos DS (2003). "Cloning, overexpression, and purification of functional human purine nucleoside phosphorylase." Protein Expr Purif 27(1);158-64. PMID: 12509998
Stein81: Stein RL, Cordes EH (1981). "Kinetic alpha-deuterium isotope effects for Escherichia coli purine nucleoside phosphorylase-catalyzed phosphorolysis of adenosine and inosine." J Biol Chem 256(2);767-72. PMID: 6778874
Stoychev02: Stoychev G, Kierdaszuk B, Shugar D (2002). "Xanthosine and xanthine. Substrate properties with purine nucleoside phosphorylases, and relevance to other enzyme systems." Eur J Biochem 269(16);4048-57. PMID: 12180982
©2014 SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025-3493