If the cell dimensions are huge and this is what dictates the
resolution/diffractibility, I will think the results may be
reasonable, at least theoretically. In this regard, further stronger
X-ray helps better resolution. LJL
On Nov 10, 2008, at 5:36 PM, Jan Abendroth wrote:
Hi all,
I have a number of low-ish resolution data sets that show a strange
B-factor behaviour:
All are just better than 3AA resolution, collected on a strong
synchrotron beamline. Some, yet not tremendous radiation decay.
Wilson scaling, obviously not very reliable at this resolution,
gives me a Wilson B of about 40, already a low number. Refinement in
refmac5 (5.5.0053) with individual B-factors refinement leads to an
average B factor of around 16 with several individual B factors
hitting the B=2 limit...
When I convert Is to Fs in truncate simply using the square root,
things get even a bit worse, the average B now is 14.
When I try to do an overall B-factor refinement, still individual B-
factors appear in the output file.
refinement details: 2.8AA resolution,medium ncs for two ncs related
chains, no riding hydrogens, simple scaling, MKLF target, isotropic
B factors
Rwork: 0.206, Rfree=0.286, bonds=0.018, angles=1.89 ... obviously I
could retrain a bit more...
Any ideas how to handle this? Basically, my question is: how do I
get the overall B factor to realistic numbers?
Thanks a lot for any hints
Jan
--
Jan Abendroth
deCODE biostructures
Seattle / Bainbridge Island, WA, USA
work: JAbendroth_at_decode.com
home: Jan.Abendroth_at_gmail.com
Lijun Liu, PhD
Institute of Molecular Biology
HHMI & Department of Physics
University of Oregon
Eugene, OR 97403
541-346-5176
