3ZDP:
reference: Monomeric nucleoprotein of influenza a virus., Chenavas S, Estrozi LF, Slama-Schwok A, Delmas B, Di Primo C, Baudin F, Li X, Crepin T, Ruigrok RW, PLoS Pathog. 2013 Mar;9(3):e1003275. doi: 10.1371/journal.ppat.1003275. Epub 2013, Mar 28. PMID: 23555270

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