InterPro domain: IPR029001

This entry represents the inosine triphosphate pyrophosphatase (ITPase)-like proteins. Members in this family include NTPases, such as Ham1-like protein (non-canonical purine NTP pyrophosphatase) and non-canonical purine NTP phosphatase (YjjX-like), Maf-like proteins and PRRC1.

Non-canonical purine NTP phosphatases are prokaryotic phosphatases that hydrolyse non-canonical purine nucleotides such as XTP and ITP to their respective diphosphate derivatives [ 1 ].

Ham1 is a pyrophosphatase that hydrolyses the non-canonical purine nucleotides inosine triphosphate (ITP), deoxyinosine triphosphate (dITP) as well as 2'-deoxy-N-6-hydroxylaminopurine triphosphate (dHAPTP) and 5-bromodeoxyuridine 5'-triphosphate (BrdUTP) to their respective monophosphate derivatives [ 2 ].

Maf proteins exhibit nucleotide pyrophosphatase activity against canonical and modified nucleotides [ 3 ]. Proline-rich and coiled-coil-containing protein 1 (PRRC1) is a Golgi-associated protein of unknown function [ 4 ].

1. Identification of an ITPase/XTPase in Escherichia coli by structural and biochemical analysis. Structure 13, 1511-20
2. Characterisation of multiple substrate-specific (d)ITP/(d)XTPase and modelling of deaminated purine nucleotide metabolism. BMB Rep 45, 259-64
3. Biochemical and structural studies of conserved Maf proteins revealed nucleotide pyrophosphatases with a preference for modified nucleotides. Chem. Biol. 20, 1386-98
4. Structural analysis and expression profile of a novel gene on chromosome 5q23 encoding a Golgi-associated protein with six splice variants, and involved within the 5q deletion of a Ph(-) CML patient. Leuk. Res. 29, 17-31