5GLA:
reference: High adaptability of the omega loop underlies the substrate-spectrum-extension evolution of a class A beta-lactamase, PenL., Yi H, Choi JM, Hwang J, Prati F, Cao TP, Lee SH, Kim HS, Sci Rep. 2016 Nov 9;6:36527. doi: 10.1038/srep36527. PMID: 27827433

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