Condensin loop extrusion properties, roadblocks, and role in homology search during recombination in S. cerevisiae

The in vivo mechanism, cis-acting roadblocks, and biological functions of DNA loop extrusion by eukaryotic SMC complexes remain incompletely defined. Here, we identify condensin-dependent Hi-C contact stripes at the recombination enhancer (RE) and at rDNA in S. cerevisiae. The RE is an autonomous condensin loading site only active in MATa cells from which oriented, unidirectional loop extrusion proceeds with an estimated processivity ~150-250 kb and a density ~0.04-0.18 that varies across the ce