Rad51_DMC1_radA,B. This group of recombinases includes the eukaryotic proteins RAD51, RAD55/57 and the meiosis-specific protein DMC1, and the archaeal proteins radA and radB. They are closely related to the bacterial RecA group. Rad51 proteins catalyze a similiar recombination reaction as RecA, using ATP-dependent DNA binding activity and a DNA-dependent ATPase. However, this reaction is less efficient and requires accessory proteins such as RAD55/57 .