Background：Pyrophosphatase that hydrolyzes the non-canonical purine nucleotides inosine triphosphate(ITP), deoxyinosine triphosphate(dITP) as well as 2'-deoxy-N-6-hydroxylaminopurine triposphate(dHAPTP) and xanthosine 5'-triphosphate(XTP) to their respective monophosphate derivatives. The enzyme does not distinguish between the deoxy-and ribose forms. Probably excludes non-canonical purines from RNA and DNA precursor pools, thus preventing their incorporation into RNA and DNA and avoiding chromosomal lesions.
