Characterization of SpPol4, a unique X-family DNA polymerase in Schizosaccharomyces pombe

• Type: Article in International Scientific Journal
• Date: 2005

Authors

González Barrera, S (Author) Other; Sánchez, A (Author) Other; Ruiz, JF (Author) Other; Juárez, R (Author) Other; Picher, AJ (Author) Other; Terrados, G (Author) Other; Paula B Andrade (Author) FFUP; Blanco, L (Author) Other

Journal

Title: Nucleic Acids Research

Vol. 33

Pages: 4762-4774

ISSN: 0305-1048

Publisher: Oxford University Press

Indexing

Scopus - 24 Citations

Other information

Authenticus ID: P-00N-FBS

DOI: 10.1093/nar/gki780

Abstract (EN): As predicted by the amino acid sequence, the purified protein coded by Schizosaccharomyces pombe SPAC2F7.06c is a DNA polymerase (SpPol4) whose biochemical properties resemble those of other X family (PolX) members. Thus, this new PolX is template-dependent, polymerizes in a distributive manner, lacks a detectable 3¿¿5¿ proofreading activity and its preferred substrates are small gaps with a 5¿-phosphate group. Similarly to Pol¿, SpPol4 can incorporate a ribonucleotide (rNTP) into a primer DNA. However, it is not responsible for the 1-2 rNTPs proposed to be present at the mating-type locus and those necessary for mating-type switching. Unlike Pol¿, SpPol4 lacks terminal deoxynucleotidyltransferase activity and realigns the primer terminus to alternative template bases only under certain sequence contexts and, therefore, it is less error-prone than Pol¿. Nonetheless, the biochemical properties of this gap-filling DNA polymerase are suitable for a possible role of SpPol4 in non-homologous end-joining. Unexpectedly based on sequence analysis, SpPol4 has deoxyribose phosphate lyase activity like Polß and Pol¿, and unlike Pol¿, suggesting also a role of this enzyme in base excision repair. Therefore, SpPol4 is a unique enzyme whose enzymatic properties are hybrid of those described for mammalian Polß, Pol¿ and Pol¿.

Language: English

Type (Professor's evaluation): Scientific