Structural probing of selected RNA and requirement for affinity for eIF4A. (A) Secondary structure of Δ6Δ23 RNA examined by ribonuclease sensitivity assays. Closed and open arrows indicate major cleavage points with RNase T1 and RNase A, respectively. Arrowheads indicate minor cleavage points. Nucleotide position of Δ9 deletion is indicated. Broken lines between loop 1 and internal-loop 1 indicate putative base-parings. (B) Nitrocellulose filter-binding assays of no. 20 deletions for eIF4A. Experimental procedures are the same as in Figure 2. RNA variants: (▪) no. 20; (•) Δ6Δ26; (▴) Δ9; (□) 5′R14; and (○) 3’R41. (C) Autoradiogram of RNase probing patter for Δ6Δ23 RNA. The 3′-end labeled RNA was partially digested with RNase T1 or RNase A, and subjected to 8% PAGE in the presence of 7 M urea. Alkaline digest ladders of Δ6Δ23 RNA are shown in left- and right-hand lanes (OH). Nucleotide positions are indicated.
