4YFU:
reference: The Closing Mechanism of DNA Polymerase I at Atomic Resolution., Miller BR 3rd, Beese LS, Parish CA, Wu EY, Structure. 2015 Jul 21. pii: S0969-2126(15)00269-5. doi:, 10.1016/j.str.2015.06.016. PMID: 26211612

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