3'-5' DNA helicase involved in DNA repair (PubMed:16146519, PubMed:18000056, PubMed:19096507). Required for the maintenance of genome stability by modulation of the DNA damage response and repression of crossovers. Confers resistance to genotoxic stress (PubMed:16146519, PubMed:18000056). Suppresses spontaneous homologous recombination (HR) events in somatic cells together with its partners RMI1 and TOP3A (PubMed:19096507). Contributes to the maintenance of chromosome integrity during meiosis. Involved in the removal of telomeric bridges that appear to arise during meiotic recombination. Required to resolve or dissolve MSH4-dependent telomeric associations. Does not seem required for chiasma formation (PubMed:21265901). ATP + H2O = ADP + H(+) + phosphate Associates with recombination intermediates and telomeres of meiotic chromosomes. Expressed in roots, seedlings, young leaves, shoots, shoot apical mersitem, inflorescences, flowers, siliques and seeds. By cold. Repressed by abscisic acid (ABA). Enhanced sensitivity to genotoxic stress such as UV light, methyl methanesulfonate (MMS) and mitomycin C (MMC), and hyperrecombination (HR) during cell division. Belongs to the helicase family. RecQ subfamily. Truncated N-terminus.