4CYL:
reference: The full-length cell-cell fusogen EFF-1 is monomeric and upright on the membrane., Zeev-Ben-Mordehai T, Vasishtan D, Siebert CA, Grunewald K, Nat Commun. 2014 May 28;5:3912. doi: 10.1038/ncomms4912. PMID: 24867324

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