In PyMOL Wiki, there is a “contact map visualizer” plugin providing users to inspect the protein intramolecular contacts. However, this plugin requires “PyGame”, “Tkinter”, “PIL (python image library)” and most importantly, Gromacs!
I used Fink (Mac OSX 10.6.8) to successfully install Gromacs 4.1 but Fink reported problems while installing pygame. So I can generate xpm file of target protein structure by Gromacs but not inspect the contact map in PyMOL.
In contrast, I found another contact map visualizer called “CMView – Protein contact map visualization and analysis“. This program is written in Java and uses PyMOL as the molecular viewer.
Installation note (work platform: Mac OSX 10.6.8 with X11)
1. Download the CMView file, unzip it and move the folder to proper path)
3. In terminal, call “cmview.sh” and load the PDB file from “CMView” and enjoy visualizing the molecules.
While the PDB is loaded, the CMView (run in Java) will show you the contact map. You can use mouse to crop the region of interest and instantly see the contacts in the PDB file.