Dear All, Possibly a trivial question but your experience would be much appreciated:
I recently submitted a structure to PDB containing 3 DTT (dithiothreitol) molecules, or so I thought. The molecules had been imported and fitted with Coot using the Get Monomer... instruction with the code DTT. The Annotator responded, quite rightly as it turns out, as follows: Please note DTT in your coordinates has been changed to DTU since it >> has incorrect stereochemistry as DTT. >> Please review the stereochemistory in the attached validation report >> summary. >> >> You can send me corrected stereochemistry for DTT if you want it >> changed back. >> >> DTU (2R,3S)-1,4-disulfanylbutane-2,3-diol >> C4 H10 O2 S2 >> >> DTT (2R,3R)-1,4-disulfanylbutane-2,3-diol >> C4 H10 O2 S2 So, is the "DTT" monomer of Coot in fact its stereoisomer known as dithioerythritol? Should I import the correct DTT from elsewhere and re-refine or is there something else behind this? Thanks a lot for any suggestions! Emmanuel
