2L7L:
reference: Fast methionine-based solution structure determination of calcium-calmodulin complexes., Gifford JL, Ishida H, Vogel HJ, J Biomol NMR. 2011 May;50(1):71-81. Epub 2011 Mar 1. PMID: 21360154

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