1N9B:
reference: Ultrahigh resolution structure of a class A beta-lactamase: on the mechanism and specificity of the extended-spectrum SHV-2 enzyme., Nukaga M, Mayama K, Hujer AM, Bonomo RA, Knox JR, J Mol Biol 2003 Apr 18;328(1):289-301. PMID: 12684014

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