1KEH:
reference: Precursor structure of cephalosporin acylase. Insights into autoproteolytic activation in a new N-terminal hydrolase family., Kim Y, Kim S, Earnest TN, Hol WG, J Biol Chem. 2002 Jan 25;277(4):2823-9. Epub 2001 Nov 8. PMID: 11706000

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