Hi Bryan, One way is that when you find H-bonds, limit the detection to only those between two backbone atoms. E.g. I can open a structure, hide all the atoms (leaving cartoon), select backbone, and then say to find only backbone-backbone H-bonds. open 2gbp ~display sel @n,ca,c,o hbonds selRestrict both ...where "selRestrict both" indicates only finding H-bonds between atoms that are both selected. You can clear the selection with ~sel It was not necessary to hide the atoms to do this limited H-bond calculation, but you said you only wanted to show the cartoons, so I included hiding atoms in my example. See hbonds help for description of "selRestrict" option <https://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/hbonds.html> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Resource for Biocomputing, Visualization, and Informatics Department of Pharmaceutical Chemistry University of California, San Francisco P.S. in ChimeraX it is even simpler, you don't have to go through selection

On Aug 27, 2024, at 4:18 PM, Bryan Sutton via Chimera-users <chimera-users@cgl.ucsf.edu> wrote:

I can't for the life of me figure out how to display ONLY a cartoon representation of my protein and backbone H-bonds. ChimeraX keeps forcing side-chain:backbone bonds.. I don't want that. I can do it if I show the backbone atoms, but I don't want to do that either. I only want it to show ONLY backbone H-bonds.