Figure 3.

Esc2 binding to Ubc9 is required for efficient sumoylation of the STR complex, Pol2 and Mcm3. (A) A schematic of Esc2 protein domains. (DNA) DNA-binding domain that prefers to bind HJ and fork structures, (SLD1) SUMO-like domain 1, (SLD2) SUMO-like domain 2. (B) Mutating the SLD2 but not SLD1 domain of Esc2 abolishes its interaction with Ubc9 in yeast two-hybrid assays. Experiments were done and data are presented as in Figure 2B. (C) Esc2-SLD2m abolished Ubc9 interaction in vitro. Experiments were done and data are presented as in Figure 2E. Dotted line denotes removal of superfluous lanes. (D) esc2-SLD2m, but not -SLD1m, reduces sumoylation levels of the STR subunits in cells. Experiments were done and data are presented as in Figure 1A. (E) esc2-SLD2m reduces levels of monosumoylation of Pol2 and disumoylation of Mcm3 in vivo. Experiments were done and data are presented as in Figure 1B.