A box-plot from SURFPLOT showing the conformation of the His-Asp-Ser catalytic triad in the serine protease alpha-chymotrypsin, PDB code 1cho.
The grey shadows behind the sidechains are orthographic projections onto the three back walls of the box, showing the three-dimensional conformation of each sidechain. The dashed lines represent hydrogen bonds.
The output from SURFPLOT can also be rendered by Raster3D with true lighting and shadowing effects.