Hello, If you want a model specifically based on a certain template, try the Modeller Comparative tool instead. Details of how to use it are in the help page: <https://rbvi.ucsf.edu/chimerax/docs/user/tools/modeller.html> ...but here's a possible outline: (1) open the template structure (2) open the sequence of the target. If you have a sequence file (e.g. FASTA) you can open that. Or, go to the uniprot website to figure out the sequence ID that you need. E.g. to open uniprot sequence LDLR_HUMAN in ChimeraX, command: open uniprot:LDLR_HUMAN (3) associate the template structure with the target sequence, even though it is different from the sequence of the template structure. Association and how to do it: <https://rbvi.ucsf.edu/chimerax/docs/user/tools/sequenceviewer.html#associati... (4) start Modeller Comparative from the main Tools menu or the Tools menu of the sequence-window context menu #3 should work fine if the sequences are reasonably similar. If the sequences are quite different (too difficult for ChimeraX to associate correctly), you may need to make an alignment of the two sequences using some other program. Then open that sequence alignment file instead of the single sequence. Associate the template structure with its own sequence. Then proceed with #4 above. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco