|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 184.108.40.206
Enzymes and Genes:
|Escherichia coli K-12 substr. MG1655 :||xanthosine phosphorylase
|Glycine max :||purine nucleoside phosphorylase
|Homo sapiens :||purine nucleoside phosphorylase
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.
Mass balance status: Balanced.
Enzyme Commission Primary Name: purine-nucleoside phosphorylase
Enzyme Commission Synonyms: inosine phosphorylase, PNPase, PUNPI, PUNPII, inosine-guanosine phosphorylase, nucleotide phosphatase, purine deoxynucleoside phosphorylase, purine deoxyribonucleoside phosphorylase, purine nucleoside phosphorylase, purine ribonucleoside phosphorylase
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): 0.72998047 [Latendresse13]
Enzyme Commission Summary:
Specificity not completely determined. Can also catalyse ribosyltransferase reactions of the type catalysed by EC 220.127.116.11, nucleoside ribosyltransferase.
Instance reactions of [a purine ribonucleoside + phosphate ↔ a purine base + α-D-ribose-1-phosphate] (18.104.22.168):
i1: adenosine + phosphate ↔ adenine + α-D-ribose-1-phosphate (22.214.171.124)
i2: guanosine + phosphate ↔ guanine + α-D-ribose-1-phosphate (126.96.36.199/188.8.131.52)
i3: inosine + phosphate ↔ hypoxanthine + α-D-ribose-1-phosphate (184.108.40.206)
Saunders69: Saunders PP, Wilson BA, Saunders GF (1969). "Purification and comparative properties of a pyrimidine nucleoside phosphorylase from Bacillus stearothermophilus." J Biol Chem 244(13);3691-7. PMID: 4978445
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
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