1k7k

Structural highlights

Function

IXTPA_ECOLI Pyrophosphatase that catalyzes the hydrolysis of nucleoside triphosphates to their monophosphate derivatives, with a high preference for the non-canonical purine nucleotides XTP (xanthosine triphosphate), dITP (deoxyinosine triphosphate) and ITP (PubMed:12297000, PubMed:17976651). Can also efficiently hydrolyze 2'-deoxy-N-6-hydroxylaminopurine triphosphate (dHAPTP) (PubMed:17090528). Seems to function as a house-cleaning enzyme that removes non-canonical purine nucleotides from the nucleotide pool, thus preventing their incorporation into DNA/RNA and avoiding chromosomal lesions (PubMed:12297000, PubMed:12730170, PubMed:17090528). To a much lesser extent, is also able to hydrolyze GTP, dGTP and dUTP, but shows very low activity toward the canonical nucleotides dATP, dCTP and dTTP and toward 8-oxo-dGTP, purine deoxyribose triphosphate, 2-aminopurine deoxyribose triphosphate and 2,6-diaminopurine deoxyribose triphosphate (PubMed:12297000, PubMed:17090528).[HAMAP-Rule:MF_01405]^{[1] [2] [3] [4]}

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

References

1. ↑ Chung JH, Park HY, Lee JH, Jang Y. Identification of the dITP J Biochem Mol Biol. 2002 Jul 31;35(4):403-8. PMID:12297000 doi:10.5483/bmbrep.2002.35.4.403
2. ↑ Burgis NE, Brucker JJ, Cunningham RP. Repair system for noncanonical purines in Escherichia coli. J Bacteriol. 2003 May;185(10):3101-10. PMID:12730170 doi:10.1128/JB.185.10.3101-3110.2003
3. ↑ Burgis NE, Cunningham RP. Substrate specificity of RdgB protein, a deoxyribonucleoside triphosphate pyrophosphohydrolase. J Biol Chem. 2007 Feb 9;282(6):3531-8. Epub 2006 Nov 6. PMID:17090528 doi:M608708200
4. ↑ Savchenko A, Proudfoot M, Skarina T, Singer A, Litvinova O, Sanishvili R, Brown G, Chirgadze N, Yakunin AF. Molecular basis of the antimutagenic activity of the house-cleaning inosine triphosphate pyrophosphatase RdgB from Escherichia coli. J Mol Biol. 2007 Dec 7;374(4):1091-103. Epub 2007 Oct 11. PMID:17976651 doi:http://dx.doi.org/10.1016/j.jmb.2007.10.012