Screw-Cap Clamp Loader Proteins that Thread
Nature Structural and Molecular Bology
Structures of the clamp loader–clamp complex reveal that nature uses machined parts in the form of a spiral scaffold (the clamp loader) to thread a circlet (the clamp) on a helix of DNA. The scaffold is then replaced by an interpretive copying machine, the polymerase, to eventually generate the replisome for DNA replication.
Zhuang, Zhihao; Spiering, Michelle M.; Berdis, Anthony J.; Trakselis, Michael A.; and Benkovic, Stephen J., "Screw-Cap Clamp Loader Proteins that Thread" (2004). Chemistry Faculty Publications. 275.