Fig 2.

Kinetics of four way Holliday junction unwinding activity of UvsW and the effect of ssDNA binding proteins on the unwinding activity of UvsW. (A) Schematic representaion of the generation of a four way Holliday junction substrate and its unwinding catalyzed by UvsW alone or in the presence of gp32 proteins and E. coli SSB protein. Holliday junction substrate was generated as described in Experimental section. The unwinding reactions were initiated by the addition of ATP and UvsW alone or in combination with gp32 proteins or E. coli SSB protein. The different types of products expected from the reaction are shown. (B) Products of four way Holliday junction unwinding reactions catalyzed by UvsW quenched at regular time intervals resolved on a native PAGE gel (8 %) are shown (lanes 8-14). Two groups of products were generated during the reactions and they migrated differently on the gels as expected of their structures. The products of the UvsW catalyzed unwinding reactions in the presence of gp32 (lanes 15-21), gp32-A (lanes1-7) and E. coli SSB (22-28) are also included. (C) Quantitative time traces of the four way Holliday junction unwinding reactions in (B) in the presence of UvsW, UvsW/gp32, UvsW/gp32-A and UvsW/E.coli SSB are shown in red, blue, green and black, respectively.