FIGURE 4.

Molecular recognition by a folE motif RNA requires a reduced pterin moiety. (A) Chemical structures of ligands evaluated for binding by the M. loti 62 folE RNA. Molecule names (see legend to Fig. 1A for abbreviation descriptions) are colored green if they are bound by the RNA, and red if they are rejected. Based on the data in B, the variable groups (left box) are not involved in molecular recognition, whereas the chemical states of the atoms at positions 5 and 8 are critical (right box). (B) PAGE analysis of in-line probing assays with the M. loti 62 folE RNA construct with THF and its various chemical derivatives. Additional annotations are as described for Figure 2B.