Hi all, I have some pdb files of ligand binding protein structures, and when I check these structures with the ribbon diagram (Presets -> Interactive 1 (ribbons)) with chimera, it not only show the "ribbon" but also the sidechain of some residues. I would like to know why, so I search on the Net. And I just find the site below: https://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/ribbonstyle/ribbon... It says "By default, when ribbon is shown for a residue, the mainchain atoms<https://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/ribbonstyle/ribbon...> of that residue are hidden, except where bonded to other displayed atoms (such as the sidechain)." I can't get more imformation, and still don't understand. What is the rule chimera follow to show the sidechain of certain residues? Thanks, Root