5KTF:
reference: NMR Structure of the C-Terminal Transmembrane Domain of the HDL Receptor, SR-BI, and a Functionally Relevant Leucine Zipper Motif., Chadwick AC, Jensen DR, Hanson PJ, Lange PT, Proudfoot SC, Peterson FC, Volkman BF, Sahoo D, Structure. 2017 Mar 7;25(3):446-457. doi: 10.1016/j.str.2017.01.001. Epub 2017, Feb 2. PMID: 28162952

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