3KPB:
reference: Binding of S-methyl-5'-thioadenosine and S-adenosyl-L-methionine to protein MJ0100 triggers an open-to-closed conformational change in its CBS motif pair., Lucas M, Encinar JA, Arribas EA, Oyenarte I, Garcia IG, Kortazar D, Fernandez JA, Mato JM, Martinez-Chantar ML, Martinez-Cruz LA, J Mol Biol. 2010 Feb 26;396(3):800-20. Epub 2009 Dec 21. PMID: 20026078

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