sRkB and sRkC RNAs bind to multifunctional ribosomal L7Ae protein. (A) EMSA of the 5'end-labeled 216 nt sRkB (sRkB216) and 211 nt sRkC (sRkC211) RNAs in presence of L7Ae in the same condition as in Figure 4B. (B) Footprinting of L7Ae on 5' end labeled sRkB216. No reaction control (C), digestion under denaturing conditions with RNAse T1 (T1 ladder) or alkaline hydrolysis (OH- ladder) are as indicated. The four middle lanes reveal cleavages by RNase T1 in presence or absence of the L7Ae protein (400 nM). Protected G residues are indicated. (C) Experimentally derived secondary structure of sRkB with RNase T1 cleavages in absence of L7Ae (strong cleavages with black arrows and weak with dotted arrows) and protected guanosines in presence of L7Ae (circles). The two kink turn structures (KT1 ) and (KT2) are boxed in grey.