Figure 4.

Tetrahedrons with two or three stem loops at the same vertex can be assembled to form kissing complexes. (A–C) Schematic drawings of the tetrahedrons with one stem-loop (A), two stem-loops (B) or three stem-loops (C) added to the same vertex, as observed from the top. (D) The use of two different loop sequences (represented by differently shaded circles) led to two complementary types of tetrahedrons (representative result of at least three independent repetitions). Interaction was analyzed in the presence of 11.5 mM Mg2+ by native 4% PAGE and fluorescence staining. Dimeric tetrahedron complexes are indicated by black triangles.