FIG. 5.

Heterodimer formation shows no direct interaction between the kissing loop and the G-rich sequences. The standard dimerization reaction was performed as outlined (Materials and Methods) except that, in some instances, a combination of different RNAs (1.5 nM [each] RNA) was codimerized in a single reaction mixture (lanes 6, 10, and 12). Also, reaction mixtures containing f105-339 RNA are supplemented with 0.5 μg of identical but unlabeled product. The different RNAs are indicated by numbers as follows: 1, f105-339; 2, f310-557; 3, f105-557. The positions of monomeric RNA (M), dimeric RNA (D), and heterodimers (HD) are shown to the left and right of the gel.