DNA polymerase epsilon catalytic domains are dispensable for DNA replication, DNA repair, and cell viability

DNA polymerase epsilon (Pol epsilon) is believed to play an essential catal ytic role during eukaryotic DNA replication and is thought to participate i n recombination and DNA repair. That pol epsilon is essential for progressi on through S phase and for viability in budding and fission yeasts is a cen tral element of support for that view. We show that the amino-terminal port ion of budding yeast Pol epsilon (Pol2) containing all known DNA polymerase and exonuclease motifs is dispensable for DNA replication, DNA repair, and viability. However, the carboxy-terminal portion of Pol2 is both necessary and sufficient for viability. Finally, the viability of cells lacking Pol2 catalytic function does not require intact DNA replication or damage check points.