4O30:
reference: Selective methylation of histone H3 variant H3.1 regulates heterochromatin replication., Jacob Y, Bergamin E, Donoghue MT, Mongeon V, LeBlanc C, Voigt P, Underwood CJ, Brunzelle JS, Michaels SD, Reinberg D, Couture JF, Martienssen RA, Science. 2014 Mar 14;343(6176):1249-53. doi: 10.1126/science.1248357. PMID: 24626927

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