YNMG tetraloop formation by a dyskeratosis congenita mutation in human telomerase RNA

(A) Stereoview of the solution structure ensemble of 20 lowest energy structures of DCloop RNA. Nucleotides are red (U), green (C), orange (A), and cyan (G). (B) Stereoview of the lowest energy structure of DCloop, with a major groove view of the pentaloop and hydrogen bonds for the U105-G108 base pair indicated by black dashed lines. (C) Major groove view of the DCloop pentaloop. (D) Major groove view of the HPwt pentaloop (PDB accession code: 1NA2; Theimer et al. 2003).