Dear Crystallographers, I was curious whether there has been a rigorous evaluation of ion binding sites in the structures in the pdb, by PDB-REDO or otherwise. I imagine that there is a considerably broad spectrum of habits and rigor in assigning solute blobs to ion X or water, and in fact it would be difficult in many cases to determine which ion a given blob really is, but there should be at least some fraction of ions/waters which can be shown from the x-ray data and known geometry to be X and not Y. This could be by small anomalous signals (Cl and H2O for example), geometric considerations, or something else. Maybe this does not even matter in most cases, but it might be important in others...
All the best, Jacob Keller ******************************************* Jacob Pearson Keller, PhD Looger Lab/HHMI Janelia Farms Research Campus 19700 Helix Dr, Ashburn, VA 20147 email: kell...@janelia.hhmi.org *******************************************
