4ABO:
reference: EBs recognize a nucleotide-dependent structural cap at growing microtubule ends., Maurer SP, Fourniol FJ, Bohner G, Moores CA, Surrey T, Cell. 2012 Apr 13;149(2):371-82. PMID: 22500803

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