Structural Basis of an Asymmetric Condensin ATPase Cycle

• DOI: 10.1016/j.molcel.2019.03.037
• Publication Date: 2019-06-20T14:41:31Z
• Authors: Markus Hassler; Indra A. Shaltiel; Marc Kschonsak; Bernd Simon; Fabian Merkel; Lena Thärichen; Henry J. Bailey; Jakub Macošek; Sol Bravo; Jutta Metz; Janosch Hennig; Christian H. Haering
• Keywords: Condensin; Coiled coil; AAA proteins

The condensin protein complex plays a key role in the structural organization of genomes. How ATPase activity its SMC subunits drives large-scale changes chromosome topology has remained unknown. Here we reconstruct, at near-atomic resolution, sequence events that take place during cycle. We show ATP binding induces conformational switch Smc4 head domain releases hitherto undescribed interaction with Ycs4 HEAT-repeat subunit and promotes engagement Smc2 into an asymmetric heterodimer. dimerization subsequently enables nucleotide second active site disengages Brn1 kleisin from coiled coil to open ring. These transitions architecture lay out mechanistic path for ability extrude DNA helices large loop structures.