FIG. 3.

HIV-1 p6 lysine 27 is required for covalent attachment of SUMO-1. Human 293T cells were transfected with plasmids encoding the proteins indicated above each lane. Cell lysates were probed by immunoblotting with anti-SUMO-1 antibody. Data are presented as described in the legend to Fig. 2. MW, molecular size in kilodaltons.