5OQF:
reference: The partial dissociation of MHC class I bound peptides exposes their N terminus to trimming by endoplasmic reticulum aminopeptidase 1., Papakyriakou A, Reeves E, Beton M, Mikolajek H, Douglas L, Cooper G, Elliott T, Werner JM, James E, J Biol Chem. 2018 Mar 29. pii: RA117.000313. doi: 10.1074/jbc.RA117.000313. PMID: 29599287

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