IUBMB Enzyme Nomenclature


Accepted name: XTP/dITP diphosphatase

Reaction: (1) XTP + H2O = XMP + diphosphate
(2) dITP + H2O = dIMP + diphosphate
(3) ITP + H2O = IMP + diphosphate

Other name(s): hypoxanthine/xanthine dNTP pyrophosphatase; rdgB (gene name)

Systematic name: XTP/dITP diphosphohydrolase (diphosphate-forming)

Comments: The enzymes from the bacterium Escherichia coli and the archaea Methanococcus jannaschii and Archaeoglobus fulgidus are highly specific for XTP, dITP and ITP. The activity is dependent on divalent cations, Mg2+ is preferred.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Chung, J.H., Back, J.H., Park, Y.I. and Han, Y.S. Biochemical characterization of a novel hypoxanthine/xanthine dNTP pyrophosphatase from Methanococcus jannaschii. Nucleic Acids Res. 29 (2001) 3099-3107. [PMID: 11452035]

2. Chung, J.H., Park, H.Y., Lee, J.H. and Jang, Y. Identification of the dITP- and XTP-hydrolyzing protein from Escherichia coli. J. Biochem. Mol. Biol. 35 (2002) 403-408. [PMID: 12297000]

[EC created 2013]

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