Hi David, See the command bond, plus the "see also" commands in its man page: http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/bond.html If you didn't want to type the atom names, you can select the two atoms and then use bond sel (to create the bond) ~bond sel (to delete the bond) An approach with the menu is to select the bond (but not the flanking atoms) and then use Actions... Atoms/Bonds... delete Another way to add bonds is to add CONECT lines to the PDB file, but then you have to put in CONECT lines for that whole residue, and it can get complicated. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng@cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html On Aug 4, 2005, at 8:25 AM, David Chenoweth wrote:

Dear Chimera users,

Does anyone know how to make a new bond or delete a bond between two atoms within a PDB file using chimera?

-Thanks DC