Hello! I am a new user to CCPNMR and to NMR analysis in general. So far I have found CCPN to be intuitive and well documented, so thank you for that! However, I am running into problems trying to import assigned chemical shift lists.
Our previous collaborators provided assignment files for our protein of interest in PIPP format. I have converted these files to NMRSTAR format using the STARch file converter. When I attempt to import the file, I get the following error message "Loading failed: Existing NmrResidue:entryNone.None.ASP does not match residue type ‘GLY’ ". Interestingly, if I change the assignment file and remove the N terminal residue, the error persists saying that the identity of the first residue does not match the type of the next residue and the import stops after the first residue.
Unlike other topics in the forum, the assignment file only has 1 chain and the project has no other chains defined so I assume that there is something wrong/incomplete about the converted NMRSTAR file (I already checked the issues mentioned here). The Atom_chem_shift loop contains the ID, Comp_index_ID, Comp_ID, Atom_ID, and Val columns. I have attempted to “reconstruct” other parts of the NMRSTAR file (e.g., _Chem_shift_experiment loop) to see if that fixes it but no luck yet. Unfortunately, there is no proper BMRB file that we can use.
What are the minimum requirements for a NMRSTAR file type in order for its contents to be imported into CCPN? Are there additional required columns in the _Atom_chem_shift table? Any advice you can provide to help us import previous assignment files? Thank you!