A tethered-inchworm model of SMC DNA translocation

The DNA loop extrusion model is a provocative new concept explaining the formation of chromatin loops that revolutionizes understanding of genome organization. Central to this model is the structural maintenance of chromosomes (SMC) protein family, which is now thought to function as a DNA motor. In this Perspective, we review and reinterpret the current knowledge of SMC structure and function and propose a novel mechanism for SMC motor activity