Hi James,
There are lots of ways to do it, but here is the command to show all atoms of residue 10 in chain A of model #1:

show #1/A:10

You can be less specific, e.g.:

show /A:10

...meaning display residue 10 of chain A in all models (and maybe you only have one anyway)

show :10

...meaning display residue 10 in all chains and all models that have a residue 10

All of the command help pages include a usage line showing how to use the command, where "atom-spec" in the usage line links to this other page that explains all of the stuff I said above, and more (e.g. you could also use residue name, atomic element symbol, ...), including several examples:
<https://rbvi.ucsf.edu/chimerax/docs/user/commands/atomspec.html>

You can also click the link from the word "Usage" which explains the conventions in the command usage information.  Once you understand the usage of the command, it is pretty simple, as all the options will be explained in the help.

There are also many example commands in the tutorials
<https://www.rbvi.ucsf.edu/chimerax/tutorials.html>

... for example, protein-ligand binding sites
<https://www.rbvi.ucsf.edu/chimerax/docs/user/tutorials/binding-sites.html>
... delta-opioid receptor ligand bindin
<https://www.rbvi.ucsf.edu/chimerax/data/delta-opioid-jan2020/binding.html>

It is hard to answer a basic question like this completely because there are so many other ways to do it, however.  For example, you could show the sequence of the protein and select the residue from there, or Ctrl-click on its ribbon segment in the graphics window to select it, and then use the Actions menu to show the atoms, or instead of the Actions menu, you could use the icon for atom display in the toolbar across the top.

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


> On May 8, 2023, at 1:02 PM, James Raymond via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:
>
> I am having trouble understanding the manual.
> I wish to show the side chain for a particular amino acid in my protein.
> What is the command line to do this?
>
> thank you
> James Raymond
>