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[ccp4bb]: Waters at atomic resolution
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I am in the process of refining a TIM-ligand complex at
1.1 ang. resolution. R-factor is around 17.0 and anisotropic
refinement is yet to be done.
I have few questions before I treat my atoms anisotropic.
Data was collected at 100K. There are quite a few waters
which have B-values greater than 40 or so. For some these
waters electron density is not spherical suggesting that they
may be moving around.
The question is do people apply any B-value cut-off to accept the
waters ? if so what should be the meaningful value for a data
collected at 100K ?
(OR) If one want to treat these waters to have half occupacies
what is the generally recommended B-values or u*u value ?
and at what stage one should assign half occupancies, before
or after anisotropic refinement ?
looking forward to your replies,
Molecular Biophysics Unit
Indian Institute of Science
Bangalore 560 012 India.