[chimerax-users] ChimeraX change chain IDs tool not available

[Elaine Meng]

Hi Anthony,
Maybe you're actually using the 1.4 release?  The download page puts the "current release" on top, which does not contain this tool -- instead you have to go lower on the page to get the daily build.  You can check what you're running using the command "version".

More to the point, however, you probably want all the chains in one model, instead of in separate models #1.1, 1.2, etc.  If you use the "combine" command to put them into a single model, that will also rename the chains to unique IDs.  Then you would save the new combined single model to a PDB file.
<https://rbvi.ucsf.edu/chimerax/docs/user/commands/combine.html>

If you don't like which chains get which IDs, however, you can then change that around with Change Chain IDs (or "changechains" command) before saving the PDB, assuming you get the new daily build.

You probably saw this documentation on our website, which is continually updated...
<https://rbvi.ucsf.edu/chimerax/docs/user/tools/changechains.html>

If you use menu: Help... User Guide it should give you documentation synchronized with the version of the program you downloaded.

I hope this helps,
Elaine
-----
Elaine C. Meng, Ph.D.                       
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

> On Aug 2, 2022, at 10:04 AM, Rish, Anthony via ChimeraX-users <chimerax-users at cgl.ucsf.edu> wrote:
> 
> Hello,
>  
> I created a protein model with 9 separate chains and fit it to my experimental cryo-EM map. However, once I saved the new model, relative to the map, the chains were renamed to 1.1/A, 1.2/A… 1.9/A. This is no good since all chains now are labeled as A in the PDB file and programs like PyMol can’t tell the difference between the chains.
>  
> I checked the ChimeraX user guide and there is supposed to be a tool for this exact problem called change chain IDs under the Tools->Structure Editing tabs, using the command changechains, but the tool is nowhere to be found. I’m running the current build of ChimeraX as of 8/2/22. 
>  
> How can I change the chain IDs of my model?
>  
> Thanks,
> Anthony