Hello I have recently tried to use the bond rotation feature of Chimera X (Windows 10), and I have not been able to get it to work. I have tried the Bond rotation button on the toolbar, and the torsion command to no avail. The bond rotation button does not seem to do anything even when I click and drag with right click. The Torsion command states that my bond “is part of a ring/cycle and cannot be rotated” or “To set torsion, middle two atoms (/A ARG 543 N C) must be bonded;they aren't” I want to ask how do I use this function to rotate upon a simple amide bond. I am not sure am I just selecting the wrong atoms/bonds or is the function just locked for this PDB. The PDB file I am using is 7Y4P and I am trying to rotate about residues 543-544. I have also tried to do it in normal Chimera’s rotation command with no results. Thank you any advice would be welcome. Regards, Chun Po Fung