Dear Hussain MR, The chimera-users@cgl.ucsf.edu address (not the others) is recommended for asking questions about using Chimera. To change an amino acid in a protein structure, you can use the Rotamers tool (in menu under Tools… Structure Editing) or the "swapaa" command. Please see the manual: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/rotamers/framerot.html> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/swapaa.html> There are "swapaa" examples in the link above, and examples of using Rotamers in the "Structure Analysis and Comparison Tutorial": <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/tutorials/squalene.html> You can find tutorials and search the documentation using the Help menu in Chimera. I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Apr 8, 2014, at 5:07 AM, MUHAMMAD RAMZAN MANWAR <geniouschemist26@gmail.com> wrote:

Dear Dr. Ferrin, Hope this email finds you the best of your health. First of all, I did appreciate the effort that You and Your team did in the form of UCSF Chimera. Being the part of academic/government university, I have used Chimera tool for protein modeling and cited in my two articles: one published in JCB-Wiley and other in Hundawi in 2014. Current email I am sending to request for guidance about how can I substitute an amino acid (wild type to mutant residue) within protein 3D model by using Chimera. I will be thankful for your guidance, if possible. With regards Hussain MR PACER-HD, KAU, KSA