The annealing helicase HARP is recruited to DNA repair sites via an interaction with RPA

Abstract

HepA-related protein (HARP) (also known as SMARCAL1) is an ATP-driven annealing helicase that catalyzes the formation of dsDNA from complementary Replication protein A (RPA)-bound ssDNA. Here we find that HARP contains a conserved N-terminal motif that is necessary and sufficient for binding to RPA. This RPA-binding motif is not required for annealing helicase activity, but is essential for the recruitment of HARP to sites of laser-induced DNA damage. These findings suggest that the interaction of HARP with RPA increases the concentration of annealing helicase activity in the vicinity of ssDNA regions to facilitate processes such as DNA repair. © 2009 by Cold Spring Harbor Laboratory Press.