General idea of alternative structures of aptamers binding the same ligand and its specific implementation scheme for the BioRS function.
(A-С) Three structures of aptamers binding to ATP that differ in their sequence and secondary–tertiary structure. The first structure (structure-I) (Sassanfar-Szostak motif) we will name as a “rod” (A). Second structure (structure-II) will be referred to as a “cloverleaf” (B) [ 93 ]. (С) One more version of an aptamer binding ATP [ 92 ]. (D) Consensus sequences of (A) and (C), critical to the recognition and binding of a ligand, in spite of their general similarity, differ to such extent that it is infeasible to transit from one to the other by a series of mutations not losing the aptamer func... Mehr ...
(A-С) Three structures of aptamers binding to ATP that differ in their sequence and secondary–tertiary structure. The first structure (structure-I) (Sassanfar-Szostak motif) we will name as a “rod” (A). Second structure (structure-II) will be referred to as a “cloverleaf” (B) [ 93 ]. (С) One more version of an aptamer binding ATP [ 92 ]. (D) Consensus sequences of (A) and (C), critical to the recognition and binding of a ligand, in spite of their general similarity, differ to such extent that it is infeasible to transit from one to the other by a series of mutations not losing the aptamer functionality (sequences similar in both versions are framed and marked by double-headed arrows). (E) Single- and double-valued loci in our simplified version of the aptamer with alternative structures. Single-valued nucleotides, necessarily present in both structures, are given in red, those present in one of the alternative structures in black. The other positions are arbitrary. See text for details.