 From studies with E. coli γ clamp loading complex, it was suggested that domain III mediates protein-protein interactions with other AAA+ ATPases in the pre-RC, thus suggesting that the CDC6 builds a homodimer in its native form.The domains I and II form a cashew-shaped molecule that bind ATP in the cleft and additionally build the sensor motif for ATP/ADP recognition.These domains are also thought to mediate subsequent conformational changes.