4ULW:
reference: Roquin binding to target mRNAs involves a winged helix-turn-helix motif., Schuetz A, Murakawa Y, Rosenbaum E, Landthaler M, Heinemann U, Nat Commun. 2014 Dec 11;5:5701. doi: 10.1038/ncomms6701. PMID: 25504471

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