Fig 6. Chl1 DNA helicase functions in condensation.

A) In the absence of Chl1, condensation defects occur despite normal recruitment of condensin (‘?’ reflects that condensin deposition, but not cohesin deposition, occurs despite Scc2 inactivation). We hypothesize that secondary DNA structures (such as G4s and nucleosomes) reduce both Scc2 and cohesin recruitment, resulting in cohesion and condensation defects. B) Chl1 activities (resolution of DNA secondary structures, histone displacement, etc) provides for both Scc2 and cohesin recruitment, resulting in sister chromatid cohesion (trans tethering) and chromatin condensation (cis tethering). Cohesin and condensin oligomerization are shown as one of several possible mechanisms of cohesion and condensation [1], [90].