HMM Summary Page: TIGR01664

FunctionDNA 3'-phosphatase
Trusted Cutoff107.65
Domain Trusted Cutoff107.65
Noise Cutoff46.45
Domain Noise Cutoff46.45
Isology Typeequivalog_domain
EC Number3.1.3.32
HMM Length167
Gene Ontology TermGO:0000012: single strand break repair biological_process
GO:0046403: polynucleotide 3'-phosphatase activity molecular_function
AuthorSelengut J
Entry DateSep 6 2002 2:52PM
Last ModifiedFeb 14 2011 3:27PM
CommentThis model represents a family of proteins and protein domains which catalyze the dephosphorylation of DNA 3'-phosphates. It is believed that this activity is important for the repair of single-strand breaks in DNA caused by radiation or oxidative damage. This domain is often (TIGR01663 [1,2]), but not always [3,4] linked to a DNA 5'-kinase domain. The central phosphatase domain is a member of the IIIA subfamily (TIGR01662) of the haloacid dehalogenase (HAD) superfamily of aspartate-nucleophile hydrolases. As is common in this superfamily, the enzyme is magnesium dependent. A difference between this enzyme and other HAD-superfamily phosphatases is in the third conserved catalytic motif which usually contains two conserved aspartate residues believed to be involved in binding the magnesium ion. Here, the second aspartate is usually replaced by an arginine residue which may indicate an interaction with the phosphate backbone of the substrate. Alternatively, there is an additional conserved aspartate downstream of the ususal site which may indicate slightly different fold in this region.
ReferencesRN [1] RM PMID: 10446192 RT Molecular cloning of the human gene, PNKP, encoding a polynucleotide kinase 3'-phosphatase and evidence for its role in repair of DNA strand breaks caused by oxidative damage. RA Jilani A, Ramotar D, Slack C, Ong C, Yang XM, Scherer SW, Lasko DD. RL J Biol Chem 1999 Aug 20;274(34):24176-86 RN [2] RM PMID: 10446193 RT Molecular characterization of a human DNA kinase. RA Karimi-Busheri F, Daly G, Robins P, Canas B, Pappin DJ, Sgouros J, Miller GG, Fakhrai H, Davis EM, Le Beau MM, Weinfeld M. RL J Biol Chem 1999 Aug 20;274(34):24187-94 RN [3] RM PMID: 11278831 RT Uncoupling of 3'-phosphatase and 5'-kinase functions in budding yeast. Characterization of Saccharomyces cerevisiae DNA 3'-phosphatase (TPP1). RA Vance JR, Wilson TE. RL J Biol Chem 2001 May 4;276(18):15073-81 RN [4] RM PMID: 11278717 RT A plant 3'-phosphoesterase involved in the repair of DNA strand breaks generated by oxidative damage. RA Betti M, Petrucco S, Bolchi A, Dieci G, Ottonello S. RL J Biol Chem 2001 May 25;276(21):18038-45