6EKI:
reference: Structure of a hyperthermostable carbonic anhydrase identified from an active hydrothermal vent chimney., Fredslund F, Borchert MS, Poulsen JN, Mortensen SB, Perner M, Streit WR, Lo Leggio L, Enzyme Microb Technol. 2018 Jul;114:48-54. doi: 10.1016/j.enzmictec.2018.03.009. , Epub 2018 Mar 30. PMID: 29685353

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