FIG. 7.

Restoration of budding with second-site revertants. (A) Lysines were substituted for arginines at positions 121 (1RK), 135 (2RK), or both (1,2RK); for glutamates at amino acid positions 111 and 143 (1,2EK); and downstream of the L domain in p10 at R205 and Q213 (3RQ/KK). Substitutions were also created in the context of 1-5KR. (B) The percent release of mutants with additional lysines in otherwise wild-type Gag compared to Gag.GFP was determined as in the legend to Fig. 2. (C) The budding of 1-5KR with additional lysines was determined as percent release of each construct relative to its parent containing the five lysines: e.g., the percent release of 5KR;1,2EK was relative to 1,2EK normalized as 100%. Transfection, metabolic radiolabeling, immunoprecipitation, and quantitation of Gag proteins were done as in the legend to Fig. 2.