4NU0:
reference: Adenylate kinase from Streptococcus pneumoniae is essential for growth through its catalytic activity., Thach TT, Luong TT, Lee S, Rhee DK, FEBS Open Bio. 2014 Jul 8;4:672-82. doi: 10.1016/j.fob.2014.07.002. eCollection, 2014. PMID: 25180151

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