4TZ6:
reference: Molecular insights into RNA and DNA helicase evolution from the determinants of specificity for a DEAD-box RNA helicase., Mallam AL, Sidote DJ, Lambowitz AM, Elife. 2014 Dec 12;3. doi: 10.7554/eLife.04630. PMID: 25497230

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