Characteristic thermodependence of the RadA recombinase from the hyperthermophilic archaeon Desulfurococcus amylolyticus

The Desulfurococcus amylolyticus RadA protein (RadA(Da)) promotes recombination at temperatures approaching the DNA melting point. Here, analyzing ATPase of the RadA(Da) presynaptic complex, we described other distinguishing characteristics of RadA(Da). These include sensitivity to NaCl, preference for lengthy single-stranded DNA as a cofactor, protein activity at temperatures of over 100 degrees C, and bimodal ATPase activity. These characteristics suggest that RadA(Da) is a founding member of a new class of archaeal recombinases.