Extensive mutual influences of SMC complexes shape 3D genome folding.

Mammalian genomes are folded through the distinct actions of structural maintenance of chromosome (SMC) complexes, which include the chromatin loop-extruding cohesin (extrusive cohesin), the sister chromatid cohesive cohesin and the mitotic chromosome-associated condensins. Although these complexes function at different stages of the cell cycle, they exist together on chromatin during the G2-to-M phase transition, when the genome structure undergoes substantial reorganization. Yet, how the different SMC complexes affect each other and how their interactions orchestrate the dynamic folding of the three-dimensional genome remain unclear.