You have been very helpful in explaining different  items that use the command line.

I have a PDB file that was determined by NMR. Thus there are a large  number of chains number as pdb (#0.1) Chain A   etc.

So I know that I can select a single chain, and build up an image with Chains A, B, etc using the #0.1 chain number.

I want to visualize three Gly residues in one chain. So I learned that I can use the command ribbackbone  to visualize the backbone atoms of the amino acids that I  want to show. So when I use that command all the backbone atoms of the residues selected are visualized including the side chains. I also know that if I use the command ~ribbackbone  all the backbone atoms are suppressed leaving only the atoms of the side chains. I  know that without any residues or atoms specified the command applies to the whole model.

Now as I said that I  want to visualize three Gly residues in one of the chains. The Gly residue numbers are 33, 37, 38.  They are on Chain #0.1 K.

The information on the ribbackbone  in the  Chimera users guide, indicates that I should be able  to do this by using parameters termed atom-spec.  i.e. ribbackbone  atom-spec

I looked elsewhere for how to designate the parameters for atom-spec and tried a few things, but I was not able to achieve the specificity of showing the backbone atoms of only the Gly residues. I don’t think that I have to indicate that I want only the Gly residues in Chain K #0.1 because I can select the Gly residues from the sequence of Chain K #0.1.

So after this long description of what I want to do, would you kindly inform me of how I can visualize the backbone atoms of only Gly.

Thank  you

Arthur G. Szabo