I'll happily add my name to the consensus! However it's interesting
to consider why some rotation functions are frankly uninterpretable
and some, as George says, are spectacular. In fact the major cause of
failure of MR has been known for a long time; in a word:
incompleteness. The reason is obv
Dear Elanor et al,
On Mon, Mar 22, 2010 at 09:30:31AM +, Eleanor Dodson wrote:
> A peak in a self rotation does NOT mean you have a dimer or a trimer
> - just that one molecule in the asu can be related to another by the
> given operator.
Exactly - and sometimes even the notion of 'molecule'
I have to agree with Clemens and Eleanor. After I had come to the wrong
conclusion about NCS and the number of molecules in the asymmetric unit
several times I gave up using the self-rotation function. Nevertheless,
I have been shown examples (especially NCS with Cn symmetry and unsual n)
where t
I absolutely agree with Clemens; self rotation functions can mislead in
some cases, and confuse in many more.. A peak in a self rotation does
NOT mean you have a dimer or a trimer - just that one molecule in the
asu can be related to another by the given operator. So for any peak
ther are nsym*
Hi Francis,
On Thu, Mar 18, 2010 at 09:03:13AM -0600, Francis E Reyes wrote:
> Hi all
>
> I have a solved structure that crystallizes as a trimer
I guess you mean that you have 3 mol/asu? And not just "a trimer in
solution that then forms crystals", right?
> to a reasonable R/Rfree, but I'm try
Francis, I would at least compute all the maps to the same resolution,
and as I suggested earlier use all the Fobs data you have, and finally
try using E's. The differences could be due to the solvent model (or
lack of it) in the Fcalc's, though I concede that doesn't explain the
difference betwee
Hi Ian,
o yes, I didn't work out the particular case that Francis Reyes was
asking for, but intended to give a more general idea where additional
twofold NCS axes could come from, by a combination of a NCS axis
perpendicular to a crystallographic twofold axis. The image should just
support th
Dirk, I'm not sure this is right, the NCS 2-folds clearly occur at phi
= 45, 135 ..., not at phi = 30, 150 ... as required by your
explanation. Also you haven't explained the very clear peaks near
theta = 45, phi = 0. 90 ... . I won't be convinced until I see the
results from RFCORR!
Cheers
--
... and here a slightly clearer version where I numbered the NCS-related
positions 1,2,3 and their crystallographic equivalent positions
1',2',3', which makes the NCS dyads a bit easier to understand ...
Sorry for sending two pictures.
Best regards,
Dirk.
Am 19.03.10 10:31, schrieb Dirk Kost
Dear Francis Reyes,
from the self-rotation function at kappa=120 degrees, you can see that
one threefold NCS axis is perpendicular to a crystallographic twofold
axis. I haven't worked this out for your particular case, but the
combination of a threefold (n-fold) NCS axis perpendicular to a
cr
ndorf
-Original Message-
From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of
Francis E Reyes
Sent: Thursday, March 18, 2010 10:03 AM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] self rotation education
Hi all
I have a solved structure that crystallizes as a trimer to a reasona
Hi Francis, if you run my RFCORR program it will do this kind of
analysis for you (but you still might need help to understand what
it's telling you, particularly if you've never used it before!).
BTW I assume the reason that your high res limit is 3 Ang is that's
all the data you have, if not the
Hi all
I have a solved structure that crystallizes as a trimer to a reasonable
R/Rfree, but I'm trying to rationalize the peaks in my self rotation. The space
group is P212121, calculating my self rotations from 50-3A, integration radius
of 22 (the radius of my molecule is about 44). I can see
13 matches
Mail list logo
