Figure 3.

(a) Secondary structure of BBD representing the location of the cisplatin-induced cross-link found in BBD-XL. (b) Cleavage products produced by the alkali hydrolysis of isolated BBD-XL. Lanes from left to right. Control lanes (untreated BBD RNA) C: control 5′ end-labeled untreated BBD. T1: G-specific sequence ladder generated by partial nuclease digestion by RNase T1. U2: A-specific sequence ladder generated by partial nuclease digestion by RNase U2. OH⁻: Reference alkali hydrolysis ladder. BBD-XL lanes C: dPAGE-isolated BBD-XL. OH⁻ lanes: dPAGE-isolated BBD-XL treated under alkali hydrolysis conditions for increasing amounts of time (see Methods). Arrows indicate major (thick arrow, G₉) and minor (thin arrow, G₁₁) sites of platinum coordination.