Hi Lucia, Please see the User Guide, especially the Build Structure tool. See Join Models and/or Adjust Bonds sections in that tool. <https://rbvi.ucsf.edu/chimerax/docs/user/tools/buildstructure.html> We have just been discussing a similar situation previous posts to chimerax-users -- see #2 in this message for details and links to the User Guide. <https://mail.cgl.ucsf.edu/mailman/archives/list/chimerax-users@cgl.ucsf.edu/...> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Resource for Biocomputing, Visualization, and Informatics Department of Pharmaceutical Chemistry University of California, San Francisco

On Jul 15, 2024, at 2:46 AM, GAETANI, LUCIA (PGR) via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:

Hi,

I am a PhD student at the University of Warwick (UK). I am contacting you to know if I can modify a pdb structure in ChimeraX. I would need to create a covalent bond between the epsilon -NH2 group of a Lys residue and the hydroxyl group of fructose to make a bond like R-CH2-NH-R'. Is this modification possible in Chimera X? If so, how can I do this?

Best wishes, Lucia