(A) The expected secondary structures of the PreQ1-RS constructs in the
unbound (w/o Lig) and bound (w Lig) states. (B) PCA plot of the U9, U11, and U14
modified RNA in the absence (w/o Lig) and presence (w Lig) of PreQ1 ligand. All
constructs were predicted to be the correct structure in both the unbound and
bound states. Condition (A): 10 mM NaH2PO4, 25 mM NaCl, 4
mM MgCl2, 0.5 mM EDTA, pH 7.3 at 25 °C.