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, insanel
The CCP4 program rwcontents includes the data from
Carugo & Bordo, Acta Cryst D, 55, 479 (1999)
Headline figures are 1.0 waters per protein residue at 2.0A, and 1.6-1.7
waters per protein residue at 1.0A. They use mainly room temperature,
but also some cryo structures.
And, as Clemens said, you s
Hi Mark,
I attach a little plot based on a quick analysis of recent PDB entries
(between Jan 04 and Nov 06, only Xray). This shows the number of
waters (HOH residues) per ATOM record (i.e. mainly protein,
RNA/DNA). If you want the number of waters per amino-acid residue, you
could just multiply it
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 th
