I'm trying to colour a molecular surface by sequence conservation...(sorry, I think I incorrectly posted this to COOTBB the other day) I've figured out how to do it in GRASP - modify the B-factor column in the PDB file to represent the percentage conservation and then colour the surface by B-factor. I know ESPRIPT will make the modified file, but I'm having trouble generating the correct one.. I am providing ESPRIPT (expert mode, %Equivalent' scoring function) with a CLUSTALW alignment (Aligned sequences > Main alignment file) and a PDB file ('Aligned sequences' > 'Supplementary pdb' file). I get the error: 'Fatal error: wrong format in PDB file.' ..and the values in the B-factor (%Equivalent) column are all either 99 or 100 which is nonsense according to the alignment. Has anyone come across this. I don't see anything wrong with my PDB file.. Thanks, Iain