IUBMB Enzyme Nomenclature


Accepted name: hypoxanthine phosphoribosyltransferase

Reaction: IMP + diphosphate = hypoxanthine + 5-phospho-α-D-ribose 1-diphosphate

Other name(s): IMP pyrophosphorylase; transphosphoribosidase; hypoxanthine—guanine phosphoribosyltransferase; guanine phosphoribosyltransferase; GPRT; HPRT; guanosine 5'-phosphate pyrophosphorylase; IMP-GMP pyrophosphorylase; HGPRTase; 6-hydroxypurine phosphoribosyltransferase; 6-mercaptopurine phosphoribosyltransferase; GMP pyrophosphorylase; guanine-hypoxanthine phosphoribosyltransferase; guanosine phosphoribosyltransferase; guanylate pyrophosphorylase; guanylic pyrophosphorylase; inosinate pyrophosphorylase; inosine 5'-phosphate pyrophosphorylase; inosinic acid pyrophosphorylase; inosinic pyrophosphorylase; 6-mercaptopurine phosphoribosyltransferase; purine-6-thiol phosphoribosyltransferase

Systematic name: IMP:diphosphate phospho-D-ribosyltransferase

Comments: Guanine and purine-6-thiol can replace hypoxanthine.

Links to other databases: BRENDA, EXPASY, GTD, KEGG, Metacyc, PDB, CAS registry number: 9016-12-0


1. Flaks, J.G. Nucleotide synthesis from 5-phosphoribosylpyrophosphate. Methods Enzymol. 6 (1963) 136-158.

2. Kornberg, A., Lieberman, I. and Simms, E.S. Enzymatic synthesis of purine nucleotides. J. Biol. Chem. 215 (1955) 417-427.

3. Lukens, L.N. and Herrington, K.A. Enzymic formation of 6-mercaptopurine ribotide. Biochim. Biophys. Acta 24 (1957) 432-433.

4. Remy, C.N., Remy, W.T. and Buchanan, J.M. Biosynthesis of the purines. VIII. Enzymatic synthesis and utilization of α-5-phosphoribosylpyrophosphate. J. Biol. Chem. 217 (1955) 885-895.

[EC created 1961, modified 1982]

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