Green Fluorescent Protein

Cartoon model of green fluorescent protein:

http://en.wikipedia.org/wiki/Green_fluorescent_protein

based on PDB entry 2WUR:

http://www.rcsb.org/pdb/explore/explore.do?structureId=2wur

The chromophore at the center of the molecule is represented as spheres.

STL file created using VMD:

http://www.ks.uiuc.edu/Research/vmd/

The protein backbone is represented in "cartoon" form. The chromophore is represented by spheres.