1DQ3:
reference: Crystal structure of an archaeal intein-encoded homing endonuclease PI-PfuI., Ichiyanagi K, Ishino Y, Ariyoshi M, Komori K, Morikawa K, J Mol Biol 2000 Jul 21;300(4):889-901. PMID: 10891276

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