[chimerax-users] Multiplying the model around the helical cryo-EM map

[Elaine Meng]

Hi Dmitry,
The short answer is that you can see the usage in the ChimeraX log with command "usage sym" or the help page with command "help sym".

>From looking at the help, it seems that you need to get rid of the word "group" in your command, and in ChimeraX there is no model #0 so your coordinate system must be some other model number. 

The long answer is that it can be difficult to figure out what center to use, if you are not sure that the coordinates in your example command are the center you want. Yes, you can measure the center of the density map with "measure center" but perhaps that is not the center of symmetry around which you want to arrange the copies.

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


> On Nov 16, 2022, at 8:10 AM, Dmitry Semchonok via ChimeraX-users <chimerax-users at cgl.ucsf.edu> wrote:
> 
> Dear colleagues,
> 
> I am trying to multiply the model subunit into the helical density.
> I found some command for Chimera 
> 
> sym #1 group c2*h,4.328,23.27,120,1 center 191.99,191.99,191.99 coord #0. Probably I have to somehow find the centre - perhaps with this command, right? Measure center #1
> 
> 
> But not for ChimeraX. 
> So my question is, how to do that in ChimeraX? Could you please provide the usage - it would be most helpful.
> 
> Thanks in advance!
> 
> Kind regards,
> Dmitry