Figure 1.

(A) The L11, RNA and thiostrepton components of the system showing the sequences and structures (26,78) of the three components. The L11 protein is indicated in blue, the 23S RNA region in red and the thiostrepton antibiotic in green. The sequence and secondary structure of the L11 protein is shown on top. Below are the secondary structure diagram of the RNA construct used (mutations in respect to the E.coli sequence indicated in bold) and a schematic structure of the thiostrepton antibiotic in which the ‘residues’ are indicated. (B) 1D ¹H NMR spectra of the RNA imino region in 200 mM KCl and native gel-shift assays of the RNA in presence and absence of Mg²⁺ in 200 mM KCl. The conditions are indicated above the lanes: with (+) or without (−) an excess of the L11 protein and thiostrepton antibiotic.