1TFR:
reference: Structure of bacteriophage T4 RNase H, a 5' to 3' RNA-DNA and DNA-DNA exonuclease with sequence similarity to the RAD2 family of eukaryotic proteins., Mueser TC, Nossal NG, Hyde CC, Cell 1996 Jun 28;85(7):1101-12. PMID: 8674116

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