Figure 1.

Assaying for intramolecular interactions. (a) Nondenaturing 20% PAGE of ³²P-labeled repeat a in the absence of salt. The first lane contains the 14-, 20-, and 56-mer markers. The rest of the eight lanes labeled 1–8 contain 0.5–4.0 copies of repeat a in increments of 0.5 repeat. For example, lane 1, 0.5 repeat, ACAGGGG; lane 2, 1.0 repeat, ACAGGGGTGTGGGG; etc. (b) Same as a, but in the presence of 100 mM NaCl. (c) Same as for b except lanes 1–8 are repeats b and lanes 9–16 are repeats variant b. (d) Same as for b except lanes 1–8 are repeats c and lanes 9–16 are repeats variant c.