FIG. 7.

Interpretation of genetic interactions between PIF1 and DNA2. (A) Pif1 may help to make a flap during RNA removal by Dna2 during OFP. (B) Dna2 may be required for optimum elongation of telomeres by telomerase, whereas Pif1 has been shown to inhibit telomerase processivity (5). Pif1 may have a second role at telomeres in which it aids Dna2 in removal of RNA from the Okazaki fragments at the telomere. The last Okazaki fragment might have a special requirement for Pif1 helicase as there is no pol δ/PCNA present to strand displace and to recruit FEN1.