Pif1 and other members of this family are RecD-like helicases involved in maintaining genome stability through unwinding double-stranded DNAs (dsDNAs), DNA/RNA hybrids, and G quadruplex (G4) structures. The members of Pif1 helicase subfamily studied so far all appear to contribute to telomere maintenance. Pif1 is a member of the DEAD-like helicases superfamily, a diverse family of proteins involved in ATP-dependent RNA or DNA unwinding. This domain contains the ATP-binding region.