n production and purification,
* Solid background in structural biology with a publication record,
* Proficiency with protein design, engineering, and structural biology
software (PyMol, Chimera, Coot, Schrodinger etc),
* Excellent presentation skills.
Best,
Yuri
___
Yuri Iozzo, PhD
n production and purification,
* Solid background in structural biology with a publication record,
* Proficiency with protein design, engineering, and structural biology
software (PyMol, Chimera, Coot, Schrodinger etc),
* Excellent presentation skills.
Best,
Yuri
___
Yuri Iozzo, PhD
Dear Community,
I apologize for the off topic question but it is hard to resist since so many
of our colleagues are incredibly knowledgeable.
I am looking for a way to block or even remove the 2Fe-2S cluster in my enzyme.
This cluster is involved in transferring electron from the Alpha to the
Dear BB,
I am sorry for posting off-topic but it is hard not to ask when you know you
can get a good answer ;-)
I need to calculate the volume of several active sites. Nothing fancy, just a
number for comparison sake.
I understand there are probably 10 different ways/programs and I would
apprec
Dear All,
I am trying to probe the existence of a disulfide bond on the surface of my
protein.
I have attempted Ellman´s and my results were not as clear as I would have
hoped for.
I am not a sulfur/cysteine chemist and would appreciate the advice on what
experiments to try!
Thanks a bunch
YAP
Thanks for all the suggestions on and off BB.
I used the GUI Sort/Reindex to combine 6 sections then ran Pointless and Scala.
Got a data set to 2.6A Rmerge 0.12 (0.06 inner shell) and solved it in C2221.
It is a good night!
Cheers,
hello everyone,
I have collected data on a problematic crystal. (first mistake...)
Images spanning phi angles 45-80 look ok and usable, also images 229-279 are
usable (index well and merge well too).
How can I combine the 2 separate .mtz files from Mosflm when I scale them?
Attempts to process the
Dear community,
I have what seems to be a pretty decent single crystal that grew from a screen
set up 2 weeks ago.
I am trying to reproduce it but so far I have not succeeded. I am however
afraid the crystal that did form will start to deteriorate. So this brings me
to dilemma, I feel like I sho
Dear community,
The protein model I am refining has 400 amino acids (3320 atoms).
Some real quick calculations tell me that to properly refine it
anisotropically, I would need 119,520 observations. Given my unit-cell
dimension and space-group it is equivalent to about a 1.24 A complete data set.
Hi everyone,
I am trying to show that a ligand underwent catalysis during a soaking
experiment.
One of the things I would like to show is the geometry of the ligand, bond
angles/lengths, dihedrals, etc...
One of my models has a hi-res of 1.18A and the ligand density is really clear
and complete.
Thanks for all the replies {off list}.
Now it's wait and hope that this crystallization experiment is succesful.
concentrated
in either protein and/or precipitant.
Curiously I went back to look at the drops after an additional 30 min and they
all look pretty clear with no appreciable precipitation.
Has anyone encountered this situation or a similar one before?
Any input/shared experience is welcome.
Best,
Yuri
Shoot the existing crystals. Who says you will need optmization? lol
ar as quality of your data goes, unless your crystal is suffering from
radiation damage (they all do!) from those free electrons/radicals
then your data should not be affected by the bleaching.
HTH.
Yuri
Hi Jan,
I wonder if the protein has a hexaHis tag. I recently was working on a Fe-S
containing protein and noticed significant aggregation/precipitation. After I
cleaving the His tag, the enzyme seems stable for days in the same buffer.
HTH,
Yuri
complex
formation, given the high resolution crystal structures.
I would be looking for a trend, and possibly an explanation for why some
mutations do not seem to form a complex.
Thanks for your input.
Yuri
fits your
density with just that one screen shot. It doesnt really look like it to me.
I would inspect distances and angles for each of the scenarios presented above
and then build a model that makes good chemical and physical sense.
Hope his helps.
yuri
Dear community,
I am trying to cleave a hexaHis tag from my protein prior to crystallization.
As I was setting up my digestion, my protein started to precipitate as soon as
I added the recommended thrombin buffer.
My question is, if anyone has encountered this, how well does it cleave without
thr
Grinter,
I would be very careful when comparing atomic distances (or even considering
them) using a 3.1 A data set. Take a look at what error estimates are for this
resolution, given your R values ;).
Also, I second what has been said, that you should build a model that makes
"physical" sense,
I think "IGNORE" is the wrong word here, but as many have pointed out, you may
be able to deal with this situation.
Besides the many good tips that been given, I think EVAL15 (I started reading
the paper on it) should be able to deal with some overlaps pretty succesfully.
I don't know where the
Hi Dave,
I sounds to me like you are worried about 2 separate things here.
A: Am I affecting the geometry of the coordination sites with a restraint file
that is innacurate?
B:Are my electron density maps biased, and what I am seeing is not really there?
AFAIU, if you have a restraint file that
Dear community,
I am probably disturbing a sleeping bear, but I'll post anyways...
Reading the thread on hydrogen deposition with the model, I came accross
several arguments that make sense on their own, but when put together are
puzzling and dont seem to converge to an answer. (I do realize howe
and Y beam positions.
It looks to me like its just simply not reading the image file HEADER properly.
Anyone has encountered this before and has any ideas on how to get around/fix
this?
Thanks a lot!
Yuri
Hi everyone,
Sorry for the newbie type problems, but I am just starting to use ccp4 for data
processing.
Here is my problem.
After I index and integrate my images using iMOSFLM, I end up with the .mtz
files that contains, AIUI, unmerged reflections.
Next I should try to merge and scale experiment
thanks for kindly pointing that out. (despite the level of stupidity on my part)
Those were not the raw imgs... They were denzo output files. Its been a while.
Can MOSFLM work with image files of type .x (BNL X6A) ? I am having no luck...
I know it can do .cbf (BNL X25) for instance.
Thanks a lot
could it be that the scattering table would be slightly different for the
sulfur atoms at the collected wavelength?
Are they Cys or Met residues? if Cys is there a possibility of oxidation to the
disulfides?
Hello,
Probably a stupid comment on my part, but anyways, make sure your strain has a
T7 polymerase! (I have forgotten before).
And I agree with the last idea that sometimes it is worth to just start from
scratch. New construct new vector. It may simply just work.
HTH,
Yuri
Thanks for all the replies.
I will try a couple of different plates/set-ups. My favorite will be the one
that gives me a crystal ;)
but it "should" not matter)
So fire away. Is it worth it? Any succes stories? Bad experiences?
I appreciate the input
Best,
Yuri
)
grow some enzyme-substrate complex crystals...
hth
yuri
Hello Everyone,
I want to play around with some coding/programming. Just simple calculations
from an input PDB file, B factors averages, occupancies, molecular weight, so
forth...
What should I use python,C++, visual basic?
thanks
Hi Sam,
some obvious questions:
1-Space group right? ( i´d say so from your R values...)
2-Is your data good throughout all of the 180 frames? whats Rsym if take only
100?
3-how good/complete is model? Missing parts, residues, base pairs??
4-evaluate your refinement strategy...
HTH
Thanks guys
Hello Everyone,
Does anyone know of a quick (yet somewhat reliable) sort of cheat-sheet/quick
reference sheet with the more common folds with an illustrative example?
Fenghui,
What is your resolution? If your having trouble distinguishing between pro and
leu I am guessing it is
worse than 2.8 A.
You may not be able to model side chains confidently with lower resolution
data. You may have to make a call
on wether or not to model side chains, and if your model
to echo Tim's question:
If by pattern you mean the position of the spots on the film, I dont think they
would change based on the complexity of the macromolecule being studied. As far
I know it, the position of the spots are dictated by the reciprocal lattice
points
(therefore the real crystal l
correction:
You should NOT have Rwork>Rfree
generate you Rfree test
set. You should have Rwork>Rfree after refining your model.
HTH
Yuri
I also had some trouble streaming live.
So I am going to go ahead and also suggest/ask please that the video files be
made available for subscribers and/or all academic users.
Cheers,
I was actually trying to do the same thing. I have to data sets processed in
p21 that I would like to merge as one contains higher resolution data. They
were processed and merged using the HKL suite. So I have the two .sca files
I guess the first step for me would be to create " a fake unmerged s
In my personal opinion, whatever that is worth, I would question why you are
modelling a Mg2+ ion if you are having to go through some trouble to prove it
is there. If you dont see octahedral coordination to waters and or Asp/Glu it
probably is not a Mg.
HTH
Hi Ed,
I just had a chance of looking at your comment more closely.
You are right it only uses PHIC if in refmacs set up you choose to refine "with
prior phase information" -AFAIU.
So what exactly is the info contained in the output refmacX.mtz besides map
coefficients for COOT? If it is not jus
above mentioned
reasons (or both)
On Sun, 11 Dec 2011 20:41:48 -0500, Ed Pozharski wrote:
On Sun, 2011-12-11 at 05:28 +, Yuri Pompeu wrote:
In refmac however the newly generated refmacX.mtz file contains
phase
info as PHIC calculated from your model. Using this for subsequent
rounds of
PHENIX has an otpion under the reflection editor program that will create R
flags that are compatible with ccp4 programs.
Another point worth mentioning is in phenix.refine it is appropriate to use the
data.mtz files generated each round of refinement, as these are the raw data
plus the Rfree fl
Mads
--
Mads Gabrielsen, PhD
Institute of Infection, Immunology and Inflammation
College of Medical, Veterinary and Life Sciences
University of Glasgow
Room B216 /L303
GBRC
120 University place
G12 8TA
Phone: 0141 3307264 / 6180
E-mail: mads.gabriel...@glasgow.ac.uk
On 08/12/2011 05:26,
I once saw a figure showing the protein as surface, but instead of having it
coloured by atom type
or potential, it was shown by percent conservation in the family. Something
like red highly conserved, all the way to white, not conserved at all...
Now, I assume the figure was done by uploading al
st check what happens on Linux.
Meanwhile a quick fix for you: use no more than 10 characters in the
box
"Modifier to append to column labels".
Does this recipe work for you?
Andrey
On 6 Dec 2011, at 14:51, Yuri wrote:
The thing is, I did not run any command myself. I was using the GUI.
So t
Yuri
Perhaps you have used incorrect command line keys.
I have installed ccp4 using Marcins script on my Windows 7 Virtual
Box.
Then I used ccp4i to run ctruncate with my test case.
"Run > Run & View Com File" showed the following command:
ctruncate -mtzin
"C:/Users/andrey
Dear Developers,
I was trying to get ccp4 up and running on a Windows7 pc, and even though the
installation proceeds smoothly,
I cant get any task to finish succesfully.
Below is what the log file has to say about it.
I saw someone having trouble with the windows install as well. I have the
inst
Hello everyone,
Whats a "good" software for showing crystal packing and unit cell, axes , etc...
I know pymol and coot will do it but would love to hear other
possibilities/ideas.
Cheers,
Hi Boaz,
Yes indeed, the phosphate group of the molecule looks quite beautiful at 1.17A
and it has a really big peak 18sigma!
Is there a utility for calculating anomalous maps, or is it simply an option in
the refinement program?
Hello everyone,
I have a good data set to 1.17A that I solved by MR.
I come accross some sites that appear to be chlorides. I was
wondering if they could have some anomalous signal.
I also have a well ordered phosphate and a couple of S from Met´s.
How do I go about probing the signal from these?
Thanks for the help.
I believe option 3 describes my situation the best.
I am looking into it now...
Best,
Yuri
On Sat, 05 Nov 2011 16:38:11 -0400, Ed Pozharski wrote:
If you post the cad input file, it should be easy to pinpoint the
problem. As it stands, you are either:
1) Including Miller
Hello,
I am trying to merge two data sets on from 28 to 2.3 A 99% comlpeteness
with another one from 26 to 1.95A 82% completeness.
I keep getting an error saying Duplicate labels in the output file.
I am sure its something simple but I cannot seem to figure it out
Any ideas?
Thanks
Hi Napo,
i am sorry if you already answered this, why are so sure your solutions are
wrong?
Your maps do not look that bad. What kind of R's do you get?
Are you not happy with the packing of your coils?
Hello Everyone,
I have data sets that scaled fairly welll in C2 2 21, but intensity statistics
suggested twinning.
I was able to solve the structure in P1 21 1 (Rwork0.19/Rfree0.24 at 2.3A) with
OK looking maps.
I notice that I have 2-fold NCS that is paralell to the crystallographic A
axis, pe
Jacob,
By simply looking at the figures you show, it does look like you have some type
of long, maybe polymeric, molecule bound.
With that being said:
1- It is in the symmetry axis so maybe be a little noisy there
2-If you are in doubt about it being real or not check the density and how it
fits
I installed the version with python embedded in coot
And it works!!
Thanks a lot!!
On Tue, 25 Oct 2011 11:41:38 -0700, Nathaniel Echols wrote:
On Tue, Oct 25, 2011 at 11:40 AM, Yuri wrote:
Now here comes the stupid question...
How do I fix it?
Install a different coot version or is it
.
(of course in monoclinic there are certain conditions for twinning...)
3- How good is your model, is it complete, all the waters? Missing protein or
DNA?
HTH
Yuri
wrote:
> Dear Yuri
> 1) For twin refinement refmac
internally changes free reflections so that twin related reflections
belong to the same class (twin or working). However it would be good to
generate free reflections in higher space group that would include twin
and space group symmetries
subsequent refinement rounds should I keep using
the raw intensity mtz file or
the newly generated mtz with PHIC and FOM information?
Thank you
--
Yuri Pompeu
Hello everyone,
I am refining a structure to 2.4A with 2-fold NCS and twinned.
Maps look ok and Rfree is 0.27however as I start checking my validations I
notice that after refinemnt
my geomtry gets significantly worse. especially the rama plot. Initially I have
2 outliers and I end up with 32 (5
after 1 round of refmac rigid body and restrained refinement with twin law
(estimated alpha 0.47)
I am looking at 0.25 -0.29 Rwork Rfree and overall FOM 0.72.
I also defined NCS restraints...
s will increase more than 10
times). Moreover it is very likely that twin and pseudo rotation are
close to each other and estimated twin fractions may not be accurate.
>
regards
> Garib
>
> On 29 Sep 2011, at 15:03, Yuri Pompeu wrote:
>
>> After I ran DETWIN with t
just
bad waters though. phenix does not do real space when twinning is
enabled.
Any ideas here?
thank you much
On Thu, 29 Sep 2011 10:25:17 -0400, Phil Jeffrey wrote:
Yuri,
Detwinning relies on having both twin-related reflections present to
calculate either/both of the the de-twinned data
After I ran DETWIN with the estimated 0.46 alpha, my completeness for the
detwinned data is now down to 54%!!!
Is this normal behavior? (I am guessing yes since the lower symmetry untwinned
dat is P1 21 1)
These papers describe something similar to what I see.
Acta Cryst. (2001). D57, 1829-1835
Acta Cryst. (2009). D65, 388-392
Hello everyone,
I have a 2.3A data set that could be scaled in C 2 2 21 and P 1 21 1
Intensity statistics tests indicate twinning (pseudo-merohedral h,-k,-h-l in P
1 21 1)
I find a good MR solution and when I try to refine it with the twin law I get
fairly good maps and decent Rs 21-28%. I can
I solved the structure using molecular replacement. Those sigmas are simply
from my sigmaa 2mFo-DFc maps.
I was wondering if I could try and solve sort of like small molecules are
nks
Yuri
Just echoing what has been said.
I would make sure you have the right space group.
It may be worthwhile tyring to find a MR solution in different space groups
with different compositions.
Another imporatant thing is how complete is your model?
Do you have all the protein and DNA modeled in? How ma
Hi Paul,
I am running the centos5 build. After a couple of yum installs it seems to be
happy...
Except I cannot maximize the window for some reason.
Thanks for the reply.
Yuri
Hello everyone,
Could anyone tell me (or point me to) how to get COOT running on CentOS6 64-bit?
It doesnt launch due to failed dependencies, it requires packages that CentOS6
has replaced...
At least that is what it looks like to me...
Cheers,
A simple way to validate real space density fit is to look at it under
validate--->density fit anlysis in COOT.
I think even the GUI of phenix.refine at the end of a run the results give a
list of all residues that are under the user-definied RSCCoeficient.
With those two tools you should be able
This is regarding Ethan´s point, particularly:
>2) the protein has crystallized as a monomer even though it
>[sometimes] exists in solution as a dimer. The interface
>seen in the crystal is not the "real" dimer interface and
>thus the PISA score is correct.
I see the same exact interface i
I was playing around with PDBe PISA and came across the following:
For pdb entry 1OYA. The most promising interface has an area bury of around
720A^2 and DeltaG of -10.6Kcal/mol. sym_op(y,x,-z+1) and CSS of 0.039!
Assembly analysis says it has no strong indications that point to stable
quatern
Quick newbie question,
After i get my output file from baverage containing the average b-factor and
rms by residues,
How can I calculate and display the average (and or mean) B-factors?
Is there a way of calculating it by protein, ligands and solvent separately?
thank you
Thanks everyone, for the help.
--
Yuri Pompeu
Hello Everyone,
A little off topic but, what is a good way to show (publication
quality) multiple sequence alignment?
I am trying to show conserved regions in related proteins from
different organisms.
Thank you
--
Yuri Pompeu
Yes I just tried symex and it is a LOT faster... especially with 12 symm
operators...
yes I want to show crystal packing, but I know SuperSym can show the three axis
and fancy representations of unit cells, etc...
Jurgen,
I was able to make the picture i wanted the "poor man´s way".
I saved the symmetry coordinates in COOT and open all of them as objects
independently.
I just wanted to know what else I need to do to get the plugins going. I have
tried two differents ones with no success.
yone know what to do?
Thank you for your time
Best,
Yuri
cctbx module.
http://pymolwiki.org/index.php/Supercell
Cheers,
Thomas
--
Yuri Pompeu
Whats the best way to visualize all the symmetry related molecules, I
know COOT will show them as backbone.
I was looking for publication quality images...PyMol maybe?
thank you for suggestions
--
Yuri Pompeu
Hello everyone,
How does refmac5 pick atoms for B-factor refinement, particularly with the
mixed option enabled?
I dont see a place for entering a manual selection, eg resname FMN...
Thank you
I can launch the program after installing the newest package from
the Website
Thank you all,
yuri
On Mon, 1 Aug 2011 17:01:47 +,
ronan.kee...@stfc.ac.uk wrote:
> Dear Yuri,
>
> Are you still
encountering problems with this? I've made the changes to the CCP4
downloa
I can help
with this, off the board and then if we find a solution you can post it
on the BB.
>
> Iain
>
> On 7/29/2011 12:37 PM, Yuri wrote:
>
>> I
tried that too ... no success
>>
>> On Fri, 29 Jul 2011 15:28:58
-0400, Ed Pozharski wrote:
>>
>>>
py the correct one in the
ccp4.setup for sh.
> Wei-Chun
>
> On Fri, Jul 29, 2011 at 9:08 PM,
Yuri wrote:
>
>> Dear all,
>> I have just downloaded and installed the
ccp4-6.2.0.
>> It says all I should do next is source the
/setup-scripts/csh/ccp4.setup file... I have
I tried that too ... no success
On Fri, 29 Jul 2011 15:28:58 -0400, Ed Pozharski wrote:
On Fri, 2011-07-29 at 20:08 +0100, Yuri wrote:
Dear all,
I have just downloaded and installed the ccp4-6.2.0.
It says all I should do next is source the
/setup-scripts/csh/ccp4.setup file... I have done
Dear all,
I have just downloaded and installed the ccp4-6.2.0.
It says all I should do next is source the /setup-scripts/csh/ccp4.setup
file... I have done that, but I cannot launch the program...
Any help is welcome...(it is probably something really stupid on my part...)
Best,
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