3B39:
reference: Identification of a DNA primase template tracking site redefines the geometry of primer synthesis., Corn JE, Pelton JG, Berger JM, Nat Struct Mol Biol. 2008 Feb;15(2):163-9. Epub 2008 Jan 13. PMID: 18193061

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