4GXP:
reference: Chimeragenesis of distantly-related proteins by noncontiguous recombination., Smith MA, Romero PA, Wu T, Brustad EM, Arnold FH, Protein Sci. 2012 Dec 6. doi: 10.1002/pro.2202. PMID: 23225662

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