TAR RNA prevents stable PICH-2 binding to TASHET DNA. (A) The stem loop structure of TAR RNA mutants is depicted (nt 1 to 83) with the name of the mutation above. Mutations in the loop and/or in the bulge are shown in red. The red dots stand for nucleotides deletions. (B) 40 fold molar excess of indicated TAR mutant in vitro transcripts have been added in EMSA reactions that were performed as detailed in Figure 2. (C) PICH-2 intensity has been quantified by band density measurement on EMSA autoradiography. Results are expressed relative to PICH-2 intensity in the control lane 1 containing no TAR that was set to one (−).