Hi Elaine, Thanks for suggestions. I'll  try them and see how it looks. Ribbons won't do here since I want to show a w.t. protein and mutants with substrate analogues in the active site and how they fit (or clash) so I'm only showing a few residues.  Thanks again.                 Boaz Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Phone: 972-8-647-2220 ; Fax: 646-1710 Skype: boaz.shaanan‎