Topology Links RNA Secondary Structure with Global Conformation, Dynamics, and Adaptation

Abstract

RNA Structural Principles Revealed The thermodynamic principles that link RNA primary and secondary structure are well understood, but the relation to tertiary structure is unclear. To gain insight, Bailor et al. (p. 202 ) analyzed all available three-dimensional structures of an important RNA motif, the two-way junction, and found that flanking helices sample only a small percentage of possible interhelical orientations. They identified a set of general rules for the relative orientation of helices as a function of the size of the interconnecting junction. The results also rationalize how ligands stabilize specific conformations. Understanding the topological constraints that define RNA global conformation and dynamic adaptation provides guiding principles for rational manipulation of RNA structure.