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Hi everyone,
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<div class="">Right now we have one of those very difficult Rfree situations where it's impossible to generate a single meaningful Rfree set. Since we're in a bit of a hurry with this structure it would be good if someone could point me in the right direction.
We have crystals with 1542 non-H atoms in the asymmetric unit that diffract to only 3.6 Å in P65, which gives us a whopping 2300 reflections in total. 5% of this is only about 100 reflections. Luckily the protein is only a single point mutation of a wild type
that has been solved to much better resolution, so we know what it should look like and I simply want to investigate the effect of different levels of conservatism in the refinement, e.g. NCS in xyz and B, group B-factors, reference model, Ramachandran restraints
etc. However since the quality criterion for this is Rfree I'm not able to do this.</div>
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<div class="">I believe the correct approach is k-fold statistical cross-validation, but can someone remind me of the correct way to do this? I've done a bit of Googling without finding anything very helpful.</div>
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<div class="">Thanks</div>
<div class="">Derek</div>
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<div class=""><font class="Apple-style-span">________________________________________________________________________<br class="">
Derek Logan tel: +46 46 222 1443<br class="">
Associate Professor </font>mob: +46 76 8585 707<font class="Apple-style-span"><br class="">
Dept. of Biochemistry and Structural Biology </font><a href="http://www.cmps.lu.se" class="">www.cmps.lu.se</a><font class="Apple-style-span"><br class="">
Centre for Molecular Protein Science www.maxlab.lu.se/crystal</font><font class="Apple-style-span"><br class="">
Lund University, Box 124, 221 00 Lund, Sweden www.saromics.com</font></div>
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