FIG. 4.

Both A16 and G9 are required for binding A56/K2. (A) BS-C-1 cells were mock infected (M) or infected with VACV WR or vA16iA56TAPG93XFlag (with [+] or without [−] IPTG). The cells were lysed with Triton X-100 after 24 h, and the A56 protein was isolated by binding to streptavidin beads. The starting material (Start) and the affinity-purified proteins (Streptavidin) were resolved by SDS-PAGE and analyzed by Western blotting, using antibodies to the viral proteins indicated on the side. (B) HeLa cells were infected with vG9iA56TAP (with or without IPTG), and the A56 proteins were tandem affinity purified. The starting material (PreTAP) and the purified proteins (TAP) were analyzed as for panel A.