FIG. 1.
Southern analysis of Ty3 minus-strand, strong-stop DNA. (Top) Schematic diagram of Ty3 DNA, Ty3 RNA, tRNAiMet, and the predicted 120-nt minus-strand, strong-stop DNA. The vertical arrow and asterisk indicate the putative cleavage site between tRNAiMet and the minus-strand, strong-stop DNA. (Bottom) Southern blot of small VLP DNA species. Nucleic acid was isolated from VLP fractions of cells expressing wild-type Ty3 (WT) or IN-mutant Ty3, or from fractions of nontransformed cells (NTC). Numbers across the top of the gel correspond to Ala-scanning mutations (47). VLP DNA was separated on a 8% acrylamide sequencing-style gel next to a sequence ladder representing the 3′ U5 terminus of Ty3 (37). The DNA was probed with a 32P-5′-end-labeled oligonucleotide, complementary to minus-strand sequences in the U5 region of the LTR. The 120-nt minus-strand, strong-stop DNA is indicated.