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 reduced form of plastocyanin at low pH (3.8). The Cu(I) ion is trigonally co-ordinated by N(His37), S(Cys84) and S(Met92). The fourth Cu-ligand bond is broken. This form of the protein is redox-inactive. Model of Plastocyanin from Poplar based on the Protein Data Bank entry 6PCY: http://www.rcsb.org/pdb/explore/explore.do?structureId=6pcy STL file created using VMD: http://www.ks.uiuc.edu/Research/vmd/ The protein backbone is represented in "cartoon" form. The copper-binding histidine, cysteine and methionine, and copper ion are shown.Successfully made in PLA by a Replicator 2 using MakerWare 2.2.2.89. Standard resolution, 25% infill, 3 shells, raft and supports.