4R3L:
reference: Structural Basis for Substrate-specific Acetylation of Nalpha-acetyltransferase Ard1 from Sulfolobus solfataricus., Chang YY, Hsu CH, Sci Rep. 2015 Mar 2;5:8673. doi: 10.1038/srep08673. PMID: 25728374

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