FIG 5.

tRF-3019 acts as a primer for HTLV-1 reverse transcriptase. (A) Summary of the RT assay. The template consisted of an in vitro-transcribed RNA spanning HTLV-1 nt 721 to 822 modified by the addition of a 20-nt tail at the 5′ end. The template was incubated with HTLV-1 reverse transcriptase present in virus particles recovered from the culture supernatant of C91PL cells and either tRF-3019 RNA, miR-150-5p RNA (negative control), tRF-3019 DNA (positive control), or no primer. The products of the RT reactions were amplified by PCR using PCR primers Tail-s and U5-as and separated by PAGE in a 6% polyacrylamide gel, along with MspI-digested pBluescript as a size marker. (B) Composite of the ethidium bromide-stained gel. The black arrow indicates the position of the 87-bp PCR product expected using primers Tail-s and U5-as. The additional band in lane 3 indicated by the gray arrow was consistent with a product amplified by Tail-s and residual tRF-3019 DNA primer added to the RT assay. The primer sequences are reported in Table S1 in the supplemental material.