Take a look at this: Brunger, A., DeLaBarre, B., Davies, J. & Weis, W. X-ray structure determination at low resolution. ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY 65, 128-133 (2009).
The paper quotes Wayne Hendrickson (says "submitted") regarding "determinancy" point (i.e. where the number of observations becomes equal to the number of flexible torsions (of course, in this extreme case gemoetric restraints essentially become constraints and you don't refine B-factrors at all. With 50% solvent this is ~5.4A, and you are far from that limit. It is rather surprising that any reviewer anywhere would have doubts about possibility to refine structural model at 3.4A. While I don't know what the referee said *exactly*, but he/she may be unaware of this http://www.rcsb.org/pdb/statistics/histogram.do?mdcat=refine&mditem=ls_d_res_high&minLabel=0&maxLabel=5&numOfbars=10&name=Resolution On Wed, 2009-09-23 at 12:48 +0000, hugh morgan wrote: > Hi, > We are attempting to address a referees comment concerning our > data/parameter ratio for a 3.4 A structure. Although the ratio is only > 0.5, the R/Rfree is 25/29, which seems acceptable. Ideally I would > like to include a reference showing a graph or table of data:parameter > vs resolution but I have been unable to find such a paper. Please > could someone point me in the right direction. > Thanks in advance > > Hugh > > P.S. It would be nice to know if this table has been published > http://www-structmed.cimr.cam.ac.uk/Course/Basic_refinement/Refinement.html > > or something similar to this, which includes higher resolution > structures > http://dirac.cnrs-orleans.fr/plone/Members/hinsen/data-parameter-ratio-in-x-ray-structure-determination > > > --
