Fig. 7.

Proposed model for conformational identities and reaction pathways. The cartoon for LU denotes a disordered conformation of the ssDNA, and LF1 and LF2 are depicted as the parallel and antiparallel G-quadruplex structures, respectively, coordinating K⁺ ions between G-quartets. The short-lived species (SX) include SU, SF1, and SF2. The solid arrows represent the proposed reaction paths and the dashed arrows point toward the states that are favoured upon increasing K⁺ concentration or temperature. Copyright (2005) National Academy of Sciences of the United States of America [58].