1CTD:
reference: Determination of the solution structure of a synthetic two-site calcium-binding homodimeric protein domain by NMR spectroscopy., Shaw GS, Hodges RS, Sykes BD, Biochemistry 1992 Oct 13;31(40):9572-80. PMID: 1390738

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