Dear Pierre,
there is also a "Diffraction Anisotropy Server" at UCLA that does
some scaling and truncating of anisotropic data, possibly making your
crystallographic life a bit easier ... but I don't have personal
experiences with this approach.
Have a look at http://www.doe-mbi.ucla.edu/~sawaya/anisoscale/
Best regards,
Dirk.
Am 22.11.2007 um 14:43 schrieb Kay Diederichs:
Pierre Barraud schrieb:
Dear all,
I am working on a data set which is severely anisotropic, with
diffraction limits of 2.6 A along the a* and b* direction but only
3.3 A along the c* direction. I attached a screen shot of the
Anisotropic analysis (FALLOFF) output graph from SCALA.
My question is : what is the best strategy (or what are the
different strategies) in the structure resolution process (from
image integration to refinement) to make use of the maximum high
resolution information ? Actually, I am a little disorientated by
the informations I have collected.
Best regards,
Pierre
Pierre,
as you found, data integration is not harmed by anisotropy.
The relevant programs for structure solution and refinement (e.g.
sharp, molrep, phaser, refmac etc.) deal explicitly with
anisotropy; I don't think there there is a compelling need to do
something fancy. Others will correct me.
If you _do_ want an anisotropic resolution cutoff, you could use
sftools. Load all your data (i.e. up to 2.6A) into sftools. Then
multiply the length of the c axis by a factor of 2.6/3.3 , and let
sftools delete all those reflections that are beyond 2.6A now. Then
restore the original c axis and write out the remaining data.
HTH,
Kay
--
Kay Diederichs http://strucbio.biologie.uni-konstanz.de
email: [EMAIL PROTECTED] Tel +49 7531 88 4049 Fax 3183
Fachbereich Biologie, Universität Konstanz, Box M647, D-78457 Konstanz
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