The DNA polymerase domain of pole is required for rapid, efficient, and highly accurate chromosomal DNA replication, telomere length maintenance, and normal cell senescence in Saccharomyces cerevisiae

Saccharomyces cerevisiae POL2 encodes the catalytic subunit of DNA polymerase ε. This study investigates the cellular functions performed by the polymerase domain of Pol2p and its role in DNA metabolism. The pol2-16 mutation has a deletion in the catalytic domain of DNA polymerase ε that eliminates its polymerase and exonuclease activities. It is a viable mutant, which displays temperature sensitivity for growth and a defect in elongation step of chromosomal DNA replication even at permissive temperatures. This mutation is synthetic lethal in combination with temperature-sensitive mutants or the 3′- to 5′-exonuclease-deficient mutant of DNA polymerase δ in a haploid cell. These results suggest that the catalytic activity of DNA polymerase ε participates in the same pathway as DNA polymerase δ, and this is consistent with the observation that DNA polymerases δ and ε colocalize in some punctate foci on yeast chromatids during S phase. Thepol2-16 mutant senesces more rapidly than wild type strain and also has shorter telomeres. These results indicate that the DNA polymerase domain of Pol2p is required for rapid, efficient, and highly accurate chromosomal DNA replication in yeast.