Hi Matthias, For truncations in general, there is a "template-mismatch" command-line specifier that will find residues that don't match their standard templates. For example: sel template-mismatch - or maybe - sel protein & template-mismatch Explanation of "template-mismatch" specifier: <https://rbvi.ucsf.edu/chimerax/docs/user/commands/atomspec.html#builtin> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco

On Nov 5, 2023, at 3:41 AM, Vorländer,Matthias Kopano via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:

Dear ChimeraX team,

Is it possible to select all residues in a model that have been truncated to backbones rather build as a complete sidechain?

Many thanks, Matthias