2A12:
reference: A single active-site region for a group II intron., de Lencastre A, Hamill S, Pyle AM, Nat Struct Mol Biol. 2005 Jul;12(7):626-7. Epub 2005 Jun 26. PMID: 15980867

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