I am trying to add a four amino acid segment to the N-terminus of a protein in the pdb.  I can generate the four residue stretch and move its C-term close to the N-term of the structured protein.  I can then select the C' and N atoms, which are about 1.0 Angstrom apart.  At that point, I am stuck.  Not sure how to add a bond and then create a proper structure.  I've played around with Join Models, but no luck.  Without a peptide bond recognized by Chimera, ribbons are discontinuous.  Any ideas?

Many thanks,

glenn