Dear Teige, You need to first combine the models into a multichain single model, then save the single model. One way is in Model Panel (show this tool from the Favorites menu): with the mouse, highlight the rows of the models that you want to combine (left side of dialog), and click the “copy/combine” button (list of functions in right side of dialog). In the resulting dialog, choose the “rename them uniquely” option for chain IDs. Set other options as you like. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/modelpanel.html> The other way is with the “combine” command, which has analogous keyword options. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/combine.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 9, 2018, at 7:51 AM, Matthews-Palmer, Teige Rowan Seal <t.matthews-palmer14@imperial.ac.uk> wrote:

Dear Chimera-users,

I have a PDB file containing a single chain, that I have copied and applied turns about a symmetry axis. So now I have several models with transformed positions. When I save PDB>save multiple models in a single file, my output PDB does not seem to handle CHAINID properly. If my input PDB has CHAINID A and ends with TER, then my output PDB has everything as CHAINID A, no TER, and instead separates the models by MODEL 1 […] ENDMDL MODEL 2 [...etcetera]

I would like to save a PDB with these symmetrical copies as different chains A,B,C… (and not different models). Can anyone suggest a way to do this? Help greatly appreciated. Teige