Panagiotis L. Kastritis wrote:
Thank you for your immediate response. it gives an error, saying 'no such residue 1:B'
...
Can you tell me what i am doing wrong?
I would have thought it was obvious. ;) You are trying to select residue 1 in chain B, but there is no such residue. In fact, looking at 1a2k in PDB, I see that the first residue in chain B is numbered 4, so there is no residue '1' (or 2 or 3). You simply need to fix the residue numbers in your script.
Ben Webb, Modeller Caretaker -- http://www.salilab.org/modeller/ Modeller mail list: http://salilab.org/mailman/listinfo/modeller_usage