3TMM:
reference: The mitochondrial transcription and packaging factor Tfam imposes a U-turn on mitochondrial DNA., Ngo HB, Kaiser JT, Chan DC, Nat Struct Mol Biol. 2011 Oct 30;18(11):1290-6. doi: 10.1038/nsmb.2159. PMID: 22037171

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