Hi Pranav, If you mean a command, then if residue-based (i.e. you want whole residues): select ((/A & /B :<4) | (/B & /A :<4)) The thing in the middle is a vertical bar, not a letter or number. See how to specify zones and combinations: <https://rbvi.ucsf.edu/chimerax/docs/user/commands/atomspec.html#zones> <https://rbvi.ucsf.edu/chimerax/docs/user/commands/atomspec.html#combinations> If atom-based instead of residue-based use @< instead of :<, and if you don't want to include nonpolymer stuff like ligands or waters, that can also be arranged: select ((/A & /B :<4) | (/B & /A :<4)) & ::polymer_type>0 See specifying attributes like polymer_type: <https://rbvi.ucsf.edu/chimerax/docs/user/commands/atomspec.html#attributes> I'm told that in the very newest daily build there is also a GUI called from the menu: Select... Contacts that does something like the second command above, but I haven't had time to try it yet myself or document it. To list the selected residues in the Log, could use command: info residues sel see <https://rbvi.ucsf.edu/chimerax/docs/user/commands/info.html#residues> 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 10, 2022, at 4:40 PM, Pranav Shah via ChimeraX-users <chimerax-users@cgl.ucsf.edu> wrote:
Hi Elaine, How does one select atoms on one chain that are close to another chain based on a distance cut off? for eg: chain A and B form an interface. I now want to know which residues on chain A fall within a distance of 4Å from chain B and vice versa. Best, Pranav