Hi Mark, Getting reliable stats straight from the PDB is nearly impossible. Waters are commonly used to fill the gaps in difference maps, just to lower the R-factor. Just look at the density for almost any structure. You'll see that there are quite a few waters that have no density at all, insanely high B-factors, or are too far away from the other atoms to make hydrogen bonds. To get reasonable numebers you'll have to re-evaluate a numebr of PDB entries.
Best wishes, Robbie Joosten Center for Molecular and Biomolecular Informatics Nijmegen, The Netherlands > Hello everyone, > > I would like to ask for any information on reasonable, preferably > quantitatively derived values for the approximate crystallographic > H2O to residue ratio versus resolution for protein structures ? > > Any references or studies would be ideal, but rules of thumb > would also help. If there are any studies with greater detail, > such as per residue type, I'd appreciate learning of them also. > > I'd specifically like this for cryo conditions since that would > influence the results and my analysis involves structures > determined under cryo conditions. > > Thanks for any help. > > m > > _________________________________________________________________ > Catch suspicious messages before you open themwith Windows Live Hotmail. > http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_protection_0507 >
