4DM9:
reference: The co-crystal structure of ubiquitin carboxy-terminal hydrolase L1 (UCHL1) with a tripeptide fluoromethyl ketone (Z-VAE(OMe)-FMK)., Davies CW, Chaney J, Korbel G, Ringe D, Petsko GA, Ploegh H, Das C, Bioorg Med Chem Lett. 2012 Jun 15;22(12):3900-4. Epub 2012 May 4. PMID: 22617491

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