An RNA aptamer possessing a novel monovalent cation-mediated fold inhibits lysozyme catalysis by inhibiting the binding of long natural substrates

Hydroxyl radical footprinting of Lys1.2minE. The fractional hydroxyl radical cleavage for each nucleotide is shown in open bars for the free aptamer and in filled bars for the protein–aptamer complex. The secondary structure of Lys1.2minE is shown above, with regions of minE showing lysozyme protection highlighted in black, whereas regions that are more susceptible to cleavage in the presence of lysozyme are highlighted in gray.