Hello Carlos, Try these commands: select ligand & nucleic acid z<10 ~select protein z<10 I tried it on examples of nucleic acid structures with ligand and with and without protein: 6raw and 6gld, respectively. If you want just one line of commands, you can put them together with a semicolon between. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco
On Sep 13, 2019, at 11:52 AM, Carlos G. Oliver <cgoliver@protonmail.com> wrote:
Hello,
I would like to select all ligands that are within a distance of nucleic acids but above a distance from proteins.
The selection command I have so far is:
`select nucleic acid z<10 & protein z>10 & ligand`
This works for PDBs that contain both nucleic acids and protein.
However, some will only contain nucleic acids, and in this case the `protein z>10` condition will result in an empty selection even when there is a valid ligand.
I was wondering if there was a way to check whether the model contains protein to run a different selection command for each case, or to use a different selection command which handles both cases.
Thanks!
Carlos G. Oliver