4LD9:
reference: The N-terminal acetylation of Sir3 stabilizes its binding to the nucleosome core particle., Arnaudo N, Fernandez IS, McLaughlin SH, Peak-Chew SY, Rhodes D, Martino F, Nat Struct Mol Biol. 2013 Aug 11. doi: 10.1038/nsmb.2641. PMID: 23934150

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