FIG. 6.
pH-dependent dimer formation by oligoribonucleotides. (A and B) A schematic model of the K. lactis pseudoknot with five base triples (A), with the positions of the mutations (B) highlighted in gray. (C and D) Radioactively labeled CS4 and unlabeled CS3 (0.1 and 0.2 pmol, respectively) were analyzed as described in the legend to Fig. 3 and Materials and Methods. Identical gels were run simultaneously at pH 5 (C) and pH 7 (D). Single oligoribonucleotides are indicated by CS4 above and asterisks below the lanes. Lanes with mixtures of both CS3 and CS4 are indicated by the name (above) and number (below) of mutations introduced. (E) UV melting experiments were performed using various oligoribonucleotides at pH 5, 6, and 7. The Tm values were determined as described in Materials and Methods.