Clamp loaders place sliding clamps at primer-template junctions for processive DNA replication. When bound to ATP, clamp loaders are competent to bind and open the sliding clamp protein. This ternary complex can now bind to a primer-template junction, which activates the ATPase activity of the clamp loader. ATP hydrolysis causes the clamp loader to dissociate from the clamp and DNA, resulting in a loaded clamp that is competent for acting as a processivity factor for DNA polymerase. Figure adapted from .
Kelch et al. BMC Biology 2012 10:34 doi:10.1186/1741-7007-10-34