6XJX:
reference: Structural insights into the Ca(2+)-dependent gating of the human mitochondrial calcium uniporter., Wang Y, Han Y, She J, Nguyen NX, Mootha VK, Bai XC, Jiang Y, Elife. 2020 Aug 7;9. pii: 60513. doi: 10.7554/eLife.60513. PMID: 32762847

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