3SLP:
reference: Crystal structures of {lambda} exonuclease in complex with DNA suggest an electrostatic ratchet mechanism for processivity., Zhang J, McCabe KA, Bell CE, Proc Natl Acad Sci U S A. 2011 Jul 5. PMID: 21730170

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