Hi Jacob
I agree with Juergen, and just add that your Cys and Cl might not be
fully occupied.
cheers
Preben
On 9/1/11 10:03 PM, Jacob Keller wrote:
Dear Crystallographers,
I recently have been working with a 2.5 Ang SeMet peak wavelength
dataset which contains 2 cys's and also a couple of bona fide Cl ions
(reasonable b-factor/site is semi-buried/water does not work). In the
FFT anomalous difference map using PhiC from the refined model and
Dano, I can see the MSE's at ~10 sigma, but no Cl ions, even though Cl
should have f" = ~0.3 versus Se's f" = ~4, and no S's in the cys,
despite f" = 0.23e. There is really no anomalous peak at all--is it
just the smallness of the signal, or are the Se's somehow "swamping
out" the other signal? Perhaps the phases are tainted by the presence
of semet in the model?
Looking for suggestions,
Jacob Keller
*******************************************
Jacob Pearson Keller
Northwestern University
Medical Scientist Training Program
cel: 773.608.9185
email: j-kell...@northwestern.edu
*******************************************
--
J. Preben Morth, Ph.D
Group Leader
Membrane Transport Group
Nordic EMBL Partnership
Centre for Molecular Medicine Norway (NCMM)
University of Oslo
P.O.Box 1137 Blindern
0318 Oslo, Norway
Email: j.p.mo...@ncmm.uio.no
Tel: +47 2284 0794
http://www.jpmorth.dk
