Fig. 4. Target DNA-primed reverse transcription assay. Wild-type and YRT mutant RNP particles were incubated with recipient plasmid pBRR3-ltrB, which contains the Ll.LtrB target site (positions –30 to +15), or control plasmid pBRR3, which lacks the Ll.LtrB target site, in the presence of [α-³²P]dTTP and other dNTPs. Products were analyzed in a 0.7% agarose gel, which was dried and scanned with a PhosphorImager. DNA marker positions are shown to the left, and the products are identified to the right based on previous characterization (Saldanha et al., 1999). The schematic at the bottom shows the TPRT reaction, with products resulting from cDNA synthesis after partial or complete reverse splicing of the intron RNA into the DNA target site. The small asterisks indicate cDNA with the arrow indicating the direction of reverse transcription.