Plastocyanin, also called blue copper protein, is a copper-containing protein involved in electron-transfer: http://en.wikipedia.org/wiki/Plastocyanin The model is of the Cu II form of plastocyanin, with four ligands to the copper (II) ion. These are N(His37) S(Cys84) N(His87) and S(Met92). Model of Plastocyanin from Poplar based on the Protein Data Bank entry 1PLC: http://www.rcsb.org/pdb/explore/explore.do?structureId=1plc STL file created using VMD: http://www.ks.uiuc.edu/Research/vmd/ The protein backbone is represented in "cartoon" form. The copper-binding histidines, cysteine and methionine, and copper ion are shown.Successfully printed by a Replicator 2 in PLA using MakerWare(TM) 2.4.1.24, standard resolution (3 shells, 25% infill), with raft and supports. Different representations are provided as a guide to coloring the molecule by hand.