2MGU:
reference: Solution structure of calmodulin bound to the binding domain of the HIV-1 matrix protein., Vlach J, Samal AB, Saad JS, J Biol Chem. 2014 Mar 21;289(12):8697-705. doi: 10.1074/jbc.M113.543694. Epub, 2014 Feb 5. PMID: 24500712

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