4MSB:
reference: Structural insights into the effects of 2'-5' linkages on the RNA duplex., Sheng J, Li L, Engelhart AE, Gan J, Wang J, Szostak JW, Proc Natl Acad Sci U S A. 2014 Feb 25;111(8):3050-5. doi:, 10.1073/pnas.1317799111. Epub 2014 Feb 10. PMID: 24516151

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