Dear all, thank you for the valuable inputs.
I realize that one important piece of information that must be added concerns
the relative orientation of the domain for which the electron density becomes
poor upon merging data towards higher symmetry, with respect to the rest of the
protein.
We h
Hi Andre,
you should first optimize your data processing as much as possible ... try
different programs, and do test refinements against the data they give you.
Unfortunately Rwork/Rfree is a poor indicator unless the Wilson B is the same;
what is much more robust is the correlation coefficient
With a long axis, the twinning test often falsely suggest twinning, as the
spots may not be properly resolved. Thus a weak reflection may be overestimated
because it is next to a strong one, leading to the same intensity statistics
that you get in twinning
Phil
> On 6 Dec 2016, at 14:49, Elean
The twinning factors all about 0.25 do point to a higher symmetry than P21.
As others say - I would be very surprised (and would question result as a
referee) if your FreeR was not >> 30% for such low resolution data
Is the data anisotropic - often is with such a long cell edge..
If so do process
Dear Andre,
I agree with Jacob that P 42 21 2 might be the right space group, and that
and R free of 33% isn't so bad. If your electron density is poor, that
might just reflect the low resolution. Have you tried refinement with
Buster? It has a way with low-resolution data.
All best.
Andreas
What were the twinning tests like in p42212? I suspect that it is really that
spacegroup, the low Rfree is artificial (33% is not too bad at 3.9 Ang) and the
electron density is bias.
JPK
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Andre
Luis Berteli Ambrosio
Sent: Tu
Dear all,
We are currently refining a low resolution model (3.9 A max), obtained by MR.
Dataset was collected from a single crystal with one long cell axis (~620 A)
and high solvent content (74%).
Best refinement results (by far!) are obtained in Refmac, by imposing P21 sg
(20 multidomain monome
Dear all,
I should perhaps offer sincere apologies for posting the crystallography boards
with NMR news ;-).
However, I will not do that, as I sincerely hope you will see that in an era of
integration of structural methods, such opportunities can offer the chance for
excellent and exciting sc
Dear all,
there is a new BUILT of the XDS package available for academic users from
http://xds.mpimf-heidelberg.mpg.de . This fixes a number of problems with the
VERSION of Nov 1, and all users of that version should update.
We believe that this has a better background treatment in particular f
