FIG. 3.
Gag69-DHFR is not released from the membrane by HIV protease. Pr55gag and Gag69-DHFR, a p17MA mutant containing the first 69 amino acids of Gag fused to dihydrofolate reductase (DHFR), were synthesized in reticulocyte lysates, bound to membranes, and treated (+ PR) or not treated (C) with HIV-1 protease for 2 h. Membranes were reisolated, and membrane-bound (P) and soluble (S) fractions were analyzed by SDS-PAGE and autoradiography. Reticulocyte lysate-synthesized 35S-p17MA was used as a molecular weight marker (p17, left lane).