This is an occurrence of microheterogeneity and it is not all that uncommon. See Crambin as a classic prototype. Coot should be able to handle this.
The work-around you suggest creates a very different model. Residue 93A lies between 93 and 94 so you are actually inserting an entire residue into the chain. Dale Tronrud On 1/31/2017 9:54 AM, Edwin Pozharski wrote: > Whatever the rationale was, there is a structure in the PDB that has > alternate conformer of a residue listed with different residue type - A > is arginine and B is glutamine. Coot fails to load the model > complaining in the command window > > WARNING:: Error reading small-molecule cif "/home/epo/coot/foo.pdb" > There was an error reading /home/epo/coot/foo.pdb. > ERROR 42 READ: Duplicate sequence number and insertion code. > LINE #1571 > ATOM 1666 N BGLN B 93 24.448 28.340 -33.325 0.50 > 9.34 N > > No Spacegroup found for this PDB file > There was a coordinates read error > > > One way to deal with it is to take the second conformer and manually add > a sequence modifier (make it 93A), and that pdb file loads just fine. > > This is observed with Coot-0.8.8-pre, rev.6506. > > This is only a minor nuisance, of course, so I completely understand if > no fix is made to load such strange models. > > Cheers, > > Ed. > > --- > Coot verendus est > >
