You may also want to look at some other structures at similar resolution and
see what the density and interactions for their sulfates look like. E.g., if
you go to HIC-Up, get to the SO4 page and then click on the link to EDS
statistics - http://xray.bmc.uu.se/hicup/SO4/so4_eds_stats.html - it will show
you statistics for real-space R etc. for sulfates in various resolution bins.
If you go to the entry with the lowest RSR for your resolution bin, you should
get an example of a well-fitting sulfate - if you pick the highest RSR you
will probably find a pretty dodgy one. Click on the links to get to the EDS
entries and inspect the density of the sulfates.
--dvd
On Wed, 7 Apr 2010, Vellieux Frederic wrote:
> Rex Palmer wrote:
>> What seems to be a possible sulphate has been identified in our electron
>> density.
>> What steps could/should be taken to confirm or consolidate this assignment
>> that would satisfy referees?
>> Rex Palmer
>> Birkbeck College
> Geometry of the interactions (and the shape of the electron density).
> Anomalous map. Even if you have only diffraction data collected at "low
> wavelength" you can always compute an anomalous map and see if the sulphur
> shows up.
>
> Fred.
>
Best wishes,
--Gerard
******************************************************************
Gerard J. Kleywegt
Dept. of Cell & Molecular Biology University of Uppsala
Biomedical Centre Box 596
SE-751 24 Uppsala SWEDEN
http://xray.bmc.uu.se/gerard/ mailto:[log in to unmask]
******************************************************************
The opinions in this message are fictional. Any similarity
to actual opinions, living or dead, is purely coincidental.
******************************************************************
|