Figure 7.

Electrophoretic and spectroscopic analysis of the distal interaction formed between domain 3′X and 5BSL3.2 hairpin cre26. (A) Native TBM gel comparing the electrophoretic mobility of constructs SL2+3, SL2’ and X98 in the absence and presence of one molar equivalent of cre26, relative to a tRNA control. In all cases, the samples were snap-cooled in the absence of NaCl or MgCl₂, and then incubated with 1 mM MgCl₂ for 150 minutes at 25°C, with or without cre26. Conditions: 10–20 μM RNA, TBM running buffer (1 mM MgCl₂). (B) Superposition of ¹H-¹⁵N HSQC spectra of SL2’, acquired in the absence (green) and presence (blue) of one molar equivalent of an unlabeled cre26 sequence. In both cases, construct SL2’ was snap-cooled in the absence of NaCl or MgCl₂ and then incubated with 2 mM MgCl₂ for 150 minutes at 25°C, with or without cre26. Since the experiment used unlabeled cre26, all of the HN crosspeaks correspond to SL2’. Conditions: 49 μM RNA, 27°C.