1ZR4:
reference: Structure of a synaptic gammadelta resolvase tetramer covalently linked to two cleaved DNAs., Li W, Kamtekar S, Xiong Y, Sarkis GJ, Grindley ND, Steitz TA, Science 2005 Aug 19;309(5738):1210-5. Epub 2005 Jun 30. PMID: 15994378

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