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Re: [modeller_usage] model ligand



Bo Yang wrote:
I try to model the ligand into my model by following the example of "Tutorial-2: Modeling ligands in the binding site'. First, I use a template and one of my model to build a alignment of the two. Then manually change the alignment to add "/.." to the end of the structures and sequence in the alignment. And change the number of residues of the structure file in the alignment. I then do the modeling using the modified alignment. But I keep getting the error message: modeller. error: check_a_337E> structure not read in

If you use Modeller 8v2 or later, you will get a printout of the sequence mismatch which will help you here. I ran your script and got:

read_te_290E> Number of residues in the alignment and pdb files are different: 465 464
              For alignment entry:        1  1PQ2-2C8Ahem
                                 x  (mismatch at alignment position 465)
 Alignment   VTKGIVSLPPSYQICFIPV..
       PDB   VTKGIVSLPPSYQICFIPVh
     Match   ********************

i.e. your alignment lists two BLK residues, but your PDB structure contains only one HETATM residue (a heme group). So just remove one '.' from your alignment file (both for the template and the target sequence). I would also suggest that you remove the chain break (/) since in your input PDB the ligand is in the same chain (A) as the amino acids, while the chain break would force your model to put the ligand in a separate chain.

	Ben Webb, Modeller Caretaker
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