Hello.
I have a problem with chimera! i want to join two pdb file together by C-N peptide bond. Actually this is a modeling of a fusion protein that one part of its, is a protein and another part  is a linker. I need a complete structure.
I select the carbon atom from one model and nitrogen atom from another model. I use the "build structure<join modesl" menu for this purpose but  the "apply" button is inactive still and i don't know how i can  activate it!
please help me.