4YC2:
reference: Paring Down HIV Env: Design and Crystal Structure of a Stabilized Inner Domain of HIV-1 gp120 Displaying a Major ADCC Target of the A32 Region., Tolbert WD, Gohain N, Veillette M, Chapleau JP, Orlandi C, Visciano ML, Ebadi M, DeVico AL, Fouts TR, Finzi A, Lewis GK, Pazgier M, Structure. 2016 May 3;24(5):697-709. doi: 10.1016/j.str.2016.03.005. Epub 2016, Mar 31. PMID: 27041594

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