Figure 2.

SmpB binds the tRNA-like domain of full-length tmRNA. Autoradiograms of cleavage products of 5′- (right) and 3′- (left) labeled tmRNA by nuclease S₁ or lead acetate in the presence (+) or absence (−) of SmpB (750 nM). Lanes C, incubation controls; lanes G_L, RNase T₁ hydrolysis ladder; lanes A_L, RNase U₂ hydrolysis ladder; Lanes H_L alkaline hydrolysis ladder. The sequence of the RNA is indexed on the right of each panel. Asterisks indicate the nucleotide with reactivity changes in the presence of the protein. The structural domains of the RNA are indicated on the left of each panel and have been indicated on a schematic representation of tmRNA structure (top left).