1YG4:
reference: A loop 2 cytidine-stem 1 minor groove interaction as a positive determinant for pseudoknot-stimulated -1 ribosomal frameshifting., Cornish PV, Hennig M, Giedroc DP, Proc Natl Acad Sci U S A 2005 Sep 6;102(36):12694-9. Epub 2005 Aug 25. PMID: 16123125

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).