I am refining a novel structure and trying to build in the missing residues left out by AutoBuild. The problem is that Coot won't let me add terminal residues to the ends of some of the peptides. I will click on the button and then double-click on the atom, the cross hairs disappear and become an arrow again, but nothing happens. There doesn't seem to be any rhyme or reason as to which residues I can't build on. C-terminal, N-terminal, it doesn't matter and there is nothing in the pdb file to indicate why it won't work.
For those residues that it does let me build, it will not let me real space refine or regularize zone, even if I build several in a row so that there are flanking residues. I have to shut down coot and restart it to get anything to work. Any help would be appreciated, Kat
