The sequence of my structure includes a tag and I want to renumber from -7 so that the first residue is the start Met. I tried the old chimera command resrenumber = FAIL. I googled and searched the docs, read the list of commands one by one, and still could not figure it out. The API has a renumber_sequence() function but I don't understand the description (what’s "the given residues”? The chain?) and was unable to find an example on how to call this from the interface. I opened the python shell and typed: from chimerax.core.commands import run run(renumber_residues('#1/A:*', -7)) # FAIL Sorry if this is trivial, I am still completely baffled by ChimeraX despite using it for years. Thanks, Isabelle CONFIDENTIALITY NOTICE: This e-mail, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information protected by law. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.