6C2V:
reference: Simple yet functional phosphate-loop proteins., Romero Romero ML, Yang F, Lin YR, Toth-Petroczy A, Berezovsky IN, Goncearenco A, Yang W, Wellner A, Kumar-Deshmukh F, Sharon M, Baker D, Varani G, Tawfik DS, Proc Natl Acad Sci U S A. 2018 Nov 30. pii: 1812400115. doi:, 10.1073/pnas.1812400115. PMID: 30504143

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