1ECR:
reference: Structure of a replication-terminator protein complexed with DNA., Kamada K, Horiuchi T, Ohsumi K, Shimamoto N, Morikawa K, Nature 1996 Oct 17;383(6601):598-603. PMID: 8857533

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