3T0D:
reference: Ser-796 of beta-galactosidase (Escherichia coli) plays a key role in maintaining a balance between the opened and closed conformations of the catalytically important active site loop., Jancewicz LJ, Wheatley RW, Sutendra G, Lee M, Fraser ME, Huber RE, Arch Biochem Biophys. 2012 Jan 15;517(2):111-22. Epub 2011 Dec 1. PMID: 22155115

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