2PQ3:
reference: A 1.3-A structure of zinc-bound N-terminal domain of calmodulin elucidates potential early ion-binding step., Warren JT, Guo Q, Tang WJ, J Mol Biol. 2007 Nov 23;374(2):517-27. Epub 2007 Sep 21. PMID: 17942116

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