Dear colleagues,

my opinion is that we should develop methods or approaches to validate
!processing! of raw data. If this is possible. We have many validation
tools for structure refinement, but no tool to validate data
processing. In case we have this tools, there is no need to deposit
diffraction images (2-5GB instead of 10 MB). I think.
Of course, how to validate this? This might be topic for a new
discussion. I am sure, that in the very beginning of crystallography,
there were no tools to validate the structures as well. I am also sure
that some opinions may arise today. (Online server, where one can
upload the images with log files from processing?)
We should concentrate more on quality of our outcome, than on storage
of these data.

Petr


2011/10/28 Katherine Sippel <katherine.sip...@gmail.com>:
> Generally during these rigorous bb debates I prefer to stay silent and
> absorb all the information possible so that I can make an informed decision
> later on. I fear that I am compelled to contribute in this instance. In
> regards to the "does this make a difference in the biological interpretation
> stage" issue, I can state that it does. In my comparatively miniscule career
> I have run into this issue three times. The first two address Adrian's
> point...
>
>> And (b) even if they do, is this continual improvement even worthwhile?  I
>>  am always depressed at how little a model changes from an initial build to
>> the final one, even when the rfree drops from 35 to 23. All that work! - and
>> my biological interpretation would have been almost the same at the
>> beginning as at the end.
>
>
> In one instance I adopted an orphaned structure and ran it through a
> slightly more advanced refinement protocol (on the same structure factors)
> and ended up with a completely different story than the one I started with
> [1]. Another researcher in my grad lab identified mis-oriented catalytic
> residues in an existing structure from EDS server maps which affects the
> biochemistry of the catalytic mechanism [2].
>
> In another case I decided that I would reprocess some images that I had
> originally indexed and scaled in my "Ooo buttons clicky clicky" stage of
> learning crystallography and the improved structure factors revealed a
> alternate conformations for both a critical loop and ligand orientation [3].
>
> And this was all in the last 4 years. So I would posit that the answer is
> yes there are significant biological insights to be had with the capacity to
> reassess data in any form.
>
> Katherine
>
> [1] J Phys Chem Lett. 2010 Oct 7;1(19):2898-2902
> [2] Acta Crystallogr D Biol Crystallogr. 2009 Mar;65(Pt 3):294-6.
> [3] Manuscript in progress
>
> ------------
> Katherine Sippel, PhD
> Postdoctoral Associate
> Baylor College of Medicine
>



-- 
Petr Kolenko
kole...@imc.cas.cz
http://kolda.webz.cz

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