4CY4:
reference: The Cryo-EM structure of the CorA channel from Methanocaldococcus jannaschii in low magnesium conditions., Cleverley RM, Kean J, Shintre CA, Baldock C, Derrick JP, Ford RC, Prince SM, Biochim Biophys Acta. 2015 Jun 4. pii: S0005-2736(15)00180-7. doi:, 10.1016/j.bbamem.2015.06.002. PMID: 26051127

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