Significance of Uij's

[Daniel Anderson <dha@mbi.ucla.edu>]

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Dear CCP4-ers,

I have here under my left elbow a manuscript:

Patterson, W.R., Anderson, D.H., DeGrado, W.F.,
Cascio, D., Eisenberg, D. (1998?).
Centrosymmetric Bilayers in the 0.75A Resolution Structure of a
Designed Alpha-helical Peptide, D,L-Alpha-1.

The manuscript will be sent to Protein Science very soon, and I
submitted the model to the PDB yesterday (finally!).

It says, among other things, that the absolute values of the Uij's
don't have literal meaning. Without an explicit absorption correction,
the rest of the data set scales to the accidental intensity distribution
in the first image. The eventual refined Uij's absorb the scaling bias.

In the manuscript (under my left elbow, remember) it says that
the relative-valued Uij's are good enough for rigid body analyses,
but the lack of absolute scale for Uij's prevents meaningful calculation
of torsional energy barriers.

Thank you for listening to me type,

   Dan Anderson

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* Daniel Anderson, Ph.D.                   *
* 219 Molecular Biology Institute          *
* University of California at Los Angeles  *
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* Email: dha@mbi.ucla.edu                  *
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