Thanks for so many quick responses!
Actually, I have test several different cryo-protectants, including
glycerol, EG, and PEG400. I did not see much differences between these
cryo conditions. So, I choose glycerol.
I would like to test my crystals in RT. But I don't know how to do
this. Just moun
Hello,
I am playing with ccp4's reforigin to verify some MR solutions.
If I translate a copy of the pdb.org's PDB 2FKA (from spacegroup F432)
by +/-0.5 fractional in any unit cell direction, then reforigin will
find back this translation and consider it as valid for this spacegroup.
But for
Hi, Zhiyi:
You can always put a layer of oil on the top of your drop when you
open the coverslip. It will get you more time to mount the crystals.
Good luck
Meng-Chiao Ho
On Tue, 2010-01-26 at 11:48 -0500, Zhiyi Wei wrote:
> I forgot to mention a phenomenon when I did crystal mounting. I found
Tascimate can be used as the cryo as well. I have had experience with
crystals in similar condition and moved the crystals to a 20%
increased Tascimate solution and they froze well.
I agree with Ezra, room temperature mount your crystal before
freezing. It is the only way to know the true problem.
Howdy,
Within the last few years - I remember a paper discussing an examination
of disorder in the termini of structures found in the PDB. Does anyone
know the citation?
Thanks in advance,
Ezra
Greetings CCP4-ers,
The situation:
I have 10 fold NCS, and thought it would be fun to try the Rfree in thin
shells.
After using SFTOOLS (rfree 0.05 shell) to divvy up the Rfree flag,
everything went swimmingly until i looked at my REFMAC log in the section
"Things for loggraph, R factor and others
How does one calculate a simulated annealing omit map in cases of non
crystallographic symmetry? The omit map is being used to identify the
presence and configuration of a ligand and surrounding residues. The
omit region therefore will contain the ligand and residues within
hydrogen bonding
Dear Zhiyi,
Ezra is exactly right, of course. The Oxford Diffraction PX Scanner
system can assess the diffraction qualities of (putative) protein
crystals in situ - in the crystallisation plate. So, directly, you
would discover if your 'big and beautiful' crystals actually diffract
well... i
how much %PEG3350 ?
Try different additives such as glycerol, EG, MPD or smaller PEGs 200
or 400.
Try flash annealing
Try freezing directly in liquid nitrogen if you have previously frozen
your crystals in the stream
Try liquid annealing by dipping the frozen crystal into a new cryo
solutio
Dear colleagues,
We are pleased to announce that
version 2.2 of the package IL MILIONE
for protein crystal structure solution
by X-ray crystallography is now available.
It includes algorithms for:
-- initial phasing by ab initio, MR, SAD/MAD,
SIR/MIR, SIRAS/MIRAS techniques;
-- phase refine
I forgot to mention a phenomenon when I did crystal mounting. I found
that if open a coverslip, phase separation will appear in drops in
minutes and damage to the crystals.
And I have tried additive screen. The optimized crystals are really
big (a few hundred microns) with sharp edge but diffracti
A two-years postdoctoral position in protein crystallography is
available in the group of Pr. Sylvie Nessler in Gif sur Yvette (near
Paris) France. We are interested in understanding the molecular
signalling mechanisms involved in bacterial virulence. Our main
results concern structural ana
http://hamptonresearch.com/documents/product/hr000175_what_is_tacsimate_new.pdf
turns up once you use google's "I'm feeling lucky" button.
On Tue, 2010-01-26 at 15:42 +, Zhiyi Wei wrote:
> Dear all,
>
> I got a problem with my crystals. I have two total different proteins
> that both can be
First you need to establish if it is your cryo conditions or the
crystals. Depending where you are - they might have the equipment to do
a wet mount - without freezing. Yes the crystal will not last - but
then you know if the problem is in the
crystal. If it is - you need better crystals. If
Yes, that's true: coiled-coils are a nightmare, especially for molecular
replacement! Apart from potential twinning problems, the internal
symmetry and often very tight packing makes it extremely awful for MR
replacement trials. I would recommend to create at least seven models
for molecular re
It may be a good exercise to look at the possibility of weak reflections
in the
original images. Such reflections are not picked up by the automatic
methods and
could be a possible source for your problems.
Use manual spots picking in mosflm or an equivalent program. This will
ensure that
I would guess that coiled-coil structures might be difficult to solve by MR
because of multiple false solutions in a repetitive structure.
There's a lot to be said for experimental phases
Phil
On 25 Jan 2010, at 17:50, Michele Lunelli wrote:
> Dear all,
>
> I am trying to solve a structure at
Dear James,
I enjoyed your simulations.
Re your conclusion:-
"However, if the disorder is correlated across the entire mosaic domain,
then the "diffuse scatter" intensity pattern migrates from in between the
spots to influencing the spots themselves! ..Could this "correlated
disorder" be respo
Dear all,
while the Diffraction Anisotropy Server
(http://www.doe-mbi.ucla.edu/~sawaya/anisoscale/) is extremely helpful
for
the treatment of highly anisotropic datasets, I haven't found
anything that really cares about such cases during data processing. It
starts with the data processin
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