Figure 4.

Non-canonical (RISC-independent) actions of small RNA. A: TAR-derived RNA in HIV-1 transcriptional control. Effects on transcription have been reported for miRNA and other small RNA. Cleavage of a 5′ structured element (TAR, 1) in the nascent HIV-1 transcript may interact with the corresponding sequence in the integrated DNA (2) and lead to further degradation of the transcript (3), enforcing HIV latency. B: Small RNA may influence secondary/tertiary structure by binding complementary elements separated by considerable distance in the primary sequence.