1HI9:
reference: Structure of the Bacillus subtilis D-aminopeptidase DppA reveals a novel self-compartmentalizing protease., Remaut H, Bompard-Gilles C, Goffin C, Frere JM, Van Beeumen J, Nat Struct Biol 2001 Aug;8(8):674-8. PMID: 11473256

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