Wayne or Tim, I have an edited PDB file that I am trying to load into CCPNMR. I get the following error when I try and load it. Could it be that analysis needs the header information that was deleted from the original PDB file? In analysis I am only looking at the DNA portion of the Protien/DNA complex that was present in the original PDB. I removed all coordiantes dealing with the Protien, so that just the DNA would be displayed. This file is completely compatible with molecular viewing software, such as Pymol, so I know that the PDB file is not corrupt. Any ideas.... >>> Error: /Users/jec/Desktop/sppot1pndnaonly.pdb is not a file originating from PDB. Cannot be read. Trying to load structure from non-standard PDB file. Exception in Tkinter callback Traceback (most recent call last): File "/sw/lib/python2.5/lib-tk/Tkinter.py", line 1403, in __call__ return self.func(*args) File "/Applications/ccpnmr/ccpnmr1.0/python/ccpnmr/analysis/EditStructuresPopu p.py", line 277, in importStructure self.structure = getStructureFromFile(self.molSystem, file) File "/Applications/ccpnmr/ccpnmr1.0/python/ccpnmr/analysis/StructureBasic.py" , line 1183, in getStructureFromFile structure = makeStructures(dict, molSystem, doWarnings=doWarnings) File "/Applications/ccpnmr/ccpnmr1.0/python/ccpnmr/analysis/StructureBasic.py" , line 1225, in makeStructures seqIdOffset = seqIds[0] - firstSysId - seqOffset IndexError: list index out of range