IUBMB Enzyme Nomenclature


Accepted name: 5-(carboxyamino)imidazole ribonucleotide mutase

Reaction: 5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole = 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate

For diagram, click here

Other name(s): N5-CAIR mutase; PurE; N5-carboxyaminoimidazole ribonucleotide mutase; class I PurE

Systematic name: 5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole carboxymutase

Comments: In eubacteria, fungi and plants, this enzyme, along with EC, 5-(carboxyamino)imidazole ribonucleotide synthase, is required to carry out the single reaction catalysed by EC, phosphoribosylaminoimidazole carboxylase, in vertebrates [6]. In the absence of EC, phosphoribosylaminoimidazolesuccinocarboxamide synthase, the reaction is reversible [3]. The substrate is readily converted into 5-amino-1-(5-phospho-D-ribosyl)imidazole by non-enzymic decarboxylation [3].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 255379-40-9


1. Meyer, E., Leonard, N.J., Bhat, B., Stubbe, J. and Smith, J.M. Purification and characterization of the purE, purK, and purC gene products: identification of a previously unrecognized energy requirement in the purine biosynthetic pathway. Biochemistry 31 (1992) 5022-5032. [PMID: 1534690]

2. Mueller, E.J., Meyer, E., Rudolph, J., Davisson, V.J. and Stubbe, J. N5-Carboxyaminoimidazole ribonucleotide: evidence for a new intermediate and two new enzymatic activities in the de novo purine biosynthetic pathway of Escherichia coli. Biochemistry 33 (1994) 2269-2278. [PMID: 8117684]

3. Meyer, E., Kappock, T.J., Osuji, C. and Stubbe, J. Evidence for the direct transfer of the carboxylate of N5-carboxyaminoimidazole ribonucleotide (N5-CAIR) to generate 4-carboxy-5-aminoimidazole ribonucleotide catalyzed by Escherichia coli PurE, an N5-CAIR mutase. Biochemistry 38 (1999) 3012-3018. [PMID: 10074353]

4. Mathews, I.I., Kappock, T.J., Stubbe, J. and Ealick, S.E. Crystal structure of Escherichia coli PurE, an unusual mutase in the purine biosynthetic pathway. Structure 7 (1999) 1395-1406. [PMID: 10574791]

5. Firestine, S.M., Poon, S.W., Mueller, E.J., Stubbe, J. and Davisson, V.J. Reactions catalyzed by 5-aminoimidazole ribonucleotide carboxylases from Escherichia coli and Gallus gallus: a case for divergent catalytic mechanisms. Biochemistry 33 (1994) 1192711934. [PMID: 7918411]

6. Firestine, S.M., Misialek, S., Toffaletti, D.L., Klem, T.J., Perfect, J.R. and Davisson, V.J. Biochemical role of the Cryptococcus neoformans ADE2 protein in fungal de novo purine biosynthesis. Arch. Biochem. Biophys. 351 (1998) 123134. [PMID: 9500840]

[EC created 2006]

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