Hi Saverio, Models from Modeller often have different numbering than the original. If the original numbering is sequential, you can apply it to the new model(s) using the Renumber Residues tool, menu: Tools... Structure Editing... Renumber Residues, or you can use the "resrenumber" command to do the same thing. <https://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/editing/renumber.html> <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/resrenumber.html> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco

On Mar 20, 2023, at 1:24 AM, saverio via Chimera-users <chimera-users@cgl.ucsf.edu> wrote:

Hi, after a modeling a missing loop in a chain of a protein the amino acid numbering has been shifted by -1 due , I guess , to the "no corresponding structure residue" that I read in the status bar of the panel for Tool --> Sequence --> Sequence in the first position. The catalytic triad of interest now has positions X-1 , Y-1 and Z-1 instead of X,Y and Z. It is possible to restore the original numbering?

Thanks. Saverio