If wish to use acetyl-coa in model which use a polypetid as template.
How can I specify to modeller to use the atom in hetatm since I often
get other petids if I cut of the amino acid to get better alignment.
If I understand you correctly, you have multiple ligands in the template
but want only one in the model. That's straightforward - simply list all
the ligands in the *template* sequence, but only the one you want in the
*model* sequence. For example, if your template has three ligands, but
you only want the last one in the model, your alignment should look like: