1RMZ:
reference: Conformational variability of matrix metalloproteinases: beyond a single 3D structure., Bertini I, Calderone V, Cosenza M, Fragai M, Lee YM, Luchinat C, Mangani S, Terni B, Turano P, Proc Natl Acad Sci U S A. 2005 Apr 12;102(15):5334-9. Epub 2005 Apr 4. PMID: 15809432

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