Transcriptional Regulation

To function properly, RNA polymerase requires the positive transcription elongation factor P-TEFb. When not needed, P-TEFb is sequestered by the non-coding RNA 7SK. This sequestration can only occur in the presence of HEXIM protein and is mediated by the overall structure of the 7SK RNA.

7SK, a 331 nt RNA, is predicted to have 4 stem-loops (SLs). The structure of SL4 has already been solved in the lab and was published in 2010 by Durney & D’Souza. We are currently using NMR to learn more about the full 7SK molecule.