Figure 4.

A Hybrid Structural Model of the Cohesin Complex in the Gripping State

(A) Atomic model of the cohesin core docked into the negative-stain EM envelope. An atomic model of the hinge and coiled coil is placed into the rod-shaped extension. The overall density accommodates a large portion of the Psm3 coiled coil, whereas parts of Psm1 remained invisible (dashed lines). The structure of Psc3 derived from multibody refinement of the cryo-EM structure is shown, and its variable positions are indicated. The likely position of Ssl3 bound to the Mis4 N terminus is indicated.

(B) Protein crosslinks between the atomic models in the gripping state, supporting the assignments in (A).

(C) Comparison of protein crosslinks within and between the SMC coiled coils in the initial binding and gripping state.

See Figure S4 for supporting analyses of the hybrid structural model.