FIG. 2.

Characterization of VLPs isolated from WT and IN deletion mutant cells. (A) Sucrose step gradient fractionation of VLPs. VLP-associated RT activity was assayed using an oligo(dG)/poly(rC) primer template. (B) Immunoblots of gradient fractions 3 to 7 with anti-RT antibodies. For clarity, only the major bands corresponding to p63-RT are shown, except with the Δ2173-3855 mutant, in which a precursor band corresponding to unprocessed IN (Δ2173-3855)-RT is also shown. The other precursor bands observed in the WT and the Δ2173-3600 and Δ2173-3855 mutants are shown in Fig. 3.