FIG. 4.

Yku70p cofractionates with Ty1 VLPs. (A) Whole-cell extracts prepared from wild-type cells containing the induced Ty1 element (circles), wild-type cells without an induced Ty1 element (squares), and yku70 mutant cells containing the induced Ty1 element (triangles) were fractionated over a sucrose gradient and assayed for RT activity. (B) Western blot analysis of sucrose gradient fractions from panel A with anti-Yku70p antibody. Nuclear extracts from the wild-type (Wt) and yku70 (Δ70) strains were also analyzed. Yku70p is an ∼67-kDa protein recognized in wild-type extracts but not seen in yku70 extracts and is indicated by an arrow.