1CLA:
reference: Evidence for transition-state stabilization by serine-148 in the catalytic mechanism of chloramphenicol acetyltransferase., Lewendon A, Murray IA, Shaw WV, Gibbs MR, Leslie AG, Biochemistry 1990 Feb 27;29(8):2075-80. PMID: 2109633

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