Figure 1. Overall structure of the Mango-III-TO1-Biotin complex.

(a) Secondary structure of Mango-III. Thin lines with arrowheads and Leontis-Westhof symbols⁴¹ denote connectivity and base pairs, respectively. (b) Cartoon representation of the three-dimensional structure of the complex colored as in (a). Arrows indicate 5′ to 3′ chain direction, and purple and green spheres represent K⁺ and Na⁺, respectively. (c) Sequence alignment of Mango-I and Mango-III aptamer RNA cores colored as in (a). Lines depict base pairing, except for the G-quadruplex (black lines). Terminal co-varying nucleotides shaded gray.