[phenixbb] Questions about sequence file vs pdb model file in Autobuild

Dear All, Facts: -input: a sequence file, a pdb model file, an mtz file; the sequence file is the same as the pdb model except that the sequence file has 6 more residues at N-terminal; the pdb model is almost the same as my protein structure. (In a word, I just want to add a few more residues to the current pdb model. Of course I can do it in coot by manually placing residues at the N-terminal, but why not autobuild?) -problem: the output chain sequence is not the same as the sequence file (not the same as the input model file either). It misses some residues at the N-terminal and it adds some residues at the C-terminal (but disconnected from the C-terminal). Is it normal in autobuild? How to correct it? Thanks. Jason U Pitt