Re: [ccp4bb] Merging hi and low res data

2012-02-08 Thread Graeme Winter
Dear Nick, If you're happy to keep on using xia2, you can just put both of the data sets in a single directory and run xia2 -3dii /heres/where/the/data/went And wait a little while. To comment on your analysis of the statistics: inside xia2 the scaling is switched off as far as possible in the

Re: [ccp4bb] pH optimisation for crystallisation

2012-02-08 Thread Xiaodi Yu
Hello Sreetama: I think for crystallization, everything is hard to say. But if you find your crystal is sensitive to the pH, you certainly can optimize the pH value but it is better not to deviate a lot. For example you can make 0.2 unit interval (for example: pH value 4.5, 4.7, 4.9...etc

[ccp4bb] rosetta fragment viewer

2012-02-08 Thread 商元
Dear all, Is there any program that can view the fragment files generated from Rosetta Fragment library? For example, I want to build a model myself, and I know the secondary structure of the target protein, so I will dock the 9-fragment myself. But, at the first step, I have to choose one

Re: [ccp4bb] pH optimisation for crystallisation

2012-02-08 Thread Tom Peat
If you find yourself in the situation where the buffer you started with is out of range of the pH you would like to attain, there are sets of buffers you can use that contain most of the standard buffers that will give you a fairly linear response across ~4-10, as described by Newman, Acta

Re: [ccp4bb] Generating parameters/cif files for macrocyclic ligands

2012-02-08 Thread Herman . Schreuder
Hi Joel, The way I solved this problem was by generating a linear peptide and then connecting the ends using a LINK card in the header of the pdb. Good luck! Herman From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Joel Tyndall

Re: [ccp4bb] Generating parameters/cif files for macrocyclic ligands

2012-02-08 Thread Garib N Murshudov
Hi Joel Herman is right: If you are refining cyclic peptides then the easiest way is to use link record linking C-terminus with N terminus. the name of the link should be TRANS. Here is an example: LINK ALA S 21 ASN S 1TRANS It will force ALA

Re: [ccp4bb] Freezing crystal

2012-02-08 Thread Theresa H. Hsu
A little off from the original question. Why don't small crystals dissolve to make a bigger crystal, especially when the small ones grow on top of each other? Can the clustered 3D crystals (I think it is called macroscopic twin) be used for full data collection? Again, thank you. Theresa

[ccp4bb] Collecting small-molecule diffraction on a Macromolecular xtallography beam line

2012-02-08 Thread Giorgio Giardina
Hello, I have some interesting small molecule xtals. I was wondering if it is possible to collect a small molecule data-set using a sincrotron macromolecular xtallography beam line, maybe with a very low beam intensity and moving the detector as close as possible? Has anybody experienced that?

Re: [ccp4bb] Collecting small-molecule diffraction on a Macromolecular xtallography beam line

2012-02-08 Thread Tim Gruene
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hello Giorgio, most synchrotron beamlines should have a resolution limit beyond or near 1A resolution which is sufficient for solving the structure with direct methods. At least XDS has no problems with non-chiral space groups and can be used to

[ccp4bb] Dye for protein affinity measurement

2012-02-08 Thread Jiang Jiahong
Dear all, I am looking for some kind of dye for protein affinity comparison, but do not know which to choose. I know protein A can contact B to form a complex,now I hope to find something simiar with A to act as an inhibitor to block the process of A-B complex formation. Maybe a short

Re: [ccp4bb] Dye for protein affinity measurement

2012-02-08 Thread Patrick Shaw Stewart
Jiahong Thermo sells a series of kits called DyLight Fluor for fluorescent labelling of antibodies or other proteins. They have everything you need and they're very convenient and easy to use. You can pick the excitation and emission wavelength. If you label both A and B (or C) with different

[ccp4bb] What happened to JAXA

2012-02-08 Thread David Schuller
I notice links in various places to JAXA Cryoprotectant Database for protein crystals http://idb.exst.jaxa.jp/db_data/protein/200304E02478000.html But when I follow the links, I get: Forbidden - You dont have permission to access... Is this data base still available? Is there another good

Re: [ccp4bb] Dye for protein affinity measurement

2012-02-08 Thread Xiaodi Yu
Hello Jiahong: If I understand correctly that you want to test protein-protein interaction or inhibition study in solution, maybe you can try something like ELISA to test protein-protein interaction. Or if your B protein has 6 histag, you can use Ni-NTA agrose beads to test inhibition or

Re: [ccp4bb] On pKa of Aspartic acid

2012-02-08 Thread Edward A. Berry
Roger Rowlett wrote: No. Kw = [H3O+][OH-] = 1 x 10^-14 at 25 deg C. So at pH 7.0, you have 10^-7 M each at equilibrium no matter how you slice it or whatever else is in solution. If equilibrium [H3O+] goes up [OH-] goes down commensurately. The pKa of water as an acid is based on Kw and

[ccp4bb] Fwd: Re: [ccp4bb] Why don't small crystals dissolve

2012-02-08 Thread David Schuller
On 02/08/12 06:49, Enrico Stura wrote: On Wed, 08 Feb 2012 12:08:23 +0100, Theresa H. Hsu theresah...@live.com wrote: A little off from the original question. Why don't small crystals dissolve to make a bigger crystal, especially when the small ones grow on top of each other?

Re: [ccp4bb] Why don't small crystals dissolve

2012-02-08 Thread Pius Padayatti
Hi Enricho, The scenario of streak seeding follows Ostwald ripening but will this happen in other situations as follows But in a special case where you have some crystals that appear as large rods which dissolved when taken out of the incubator (or) during the observation( these were

Re: [ccp4bb] Collecting small-molecule diffraction on a Macromolecular xtallography beam line

2012-02-08 Thread Kevin Jin
I collected GTP/Mg2+ crystal on SSRL beamline 9-1 before. The images was processed by Mosflm and structure was solved by Shelx as usual. Kevin On Wed, Feb 8, 2012 at 3:41 AM, Giorgio Giardina giorgio.giard...@uniroma1.it wrote: Hello, I have some interesting small molecule xtals. I was

Re: [ccp4bb] Collecting small-molecule diffraction on a Macromolecular xtallography beam line

2012-02-08 Thread Martin Walsh
Hi Giorgio, there are beamlines dedicated to small molecule crystallography at synchrotrons as well. I can suggest I19 at Diamond (obviously) but there are others! http://www.diamond.ac.uk/Home/Beamlines/I19.html Martin -Original Message- From: CCP4 bulletin board

[ccp4bb] Post-doctoral position available

2012-02-08 Thread Meng-Chiao Ho
Dear All, The Ho lab at the Institute of Biological Chemistry of Academia Sinca in Taiwan seeks to recruit a motivated structural biologist at post-doctoral level with interest in structure and activity studies of pharmaceutically important enzymes. Applicant should have a strong background

[ccp4bb] Off topic: PyRosetta unrecognized aa Ur

2012-02-08 Thread Eike Schulz
Hello everybody, This is slightly off-topic but I still hope there might be somebody in the crowd with (Py)Rosetta experience. I successfully tried protein_protein docking before, but now I am trying to dock a RNA into a protein using PyRosetta v.1.1, which, as you can imagine, fails in a new an

Re: [ccp4bb] What happened to JAXA

2012-02-08 Thread David Schuller
It worked just as you said, but I don't read Japanese so it wasn't particularly helpful. Thanks. On 02/08/12 11:37, Clemens Vonrhein wrote: Hi, the waybackmachine at http://www.archive.org/ helps here. Just type http://idb.exst.jaxa.jp/ into the box and hit Take me back. It then

Re: [ccp4bb] What happened to JAXA

2012-02-08 Thread David Schuller
On 02/08/12 12:47, Clemens Vonrhein wrote: On Wed, Feb 08, 2012 at 12:45:35PM -0500, David Schuller wrote: It worked just as you said, but I don't read Japanese so it wasn't particularly helpful. Odd ... at

Re: [ccp4bb] Why don't small crystals dissolve

2012-02-08 Thread Enrico Stura
Pius, The situation you describe is an off-equilibrium situation. You have applied a perturbation and that may not be reversible! Enrico. On Wed, 08 Feb 2012 16:35:56 +0100, Pius Padayatti ppadaya...@gmail.com wrote: Hi Enricho, The scenario of streak seeding follows Ostwald ripening

Re: [ccp4bb] Collecting small-molecule diffraction on a Macromolecular xtallography beam line

2012-02-08 Thread Jens Kaiser
Giorgo, We have done that routinely for quite some time now. We had problems when using a normal CCD detector, where we had to collect two or three sweeps to avoid overloads (see below). Since we have the PILATUS this is not necessary anymore and the data behaves fine. Problems still persisting

Re: [ccp4bb] Collecting small-molecule diffraction on a Macromolecular xtallography beam line

2012-02-08 Thread Santarsiero, Bernard D.
Most beamlines have attenuators, so there's little reason to collect multiple sweeps. We always collect 360deg. Since it's a small molecule, and usually fairly large and robust, you can warm it up, nudge it in a different direction with a pin (we use sterile, disposable acupunture needle), and

[ccp4bb] Problems with COOT and Pymol stereo

2012-02-08 Thread Elias Fernandez
Dear CCP4ers, I'd purchased a stereo monitor from Sharper Technology with a Planar SA2311W stereo 3D LCD and the Nvidia 3D vision kit. However, I'm having a problem with the dual monitor setup. Everything works fine with Pymol and Coot when using a single 3D capable monitor (Planar SA2311W) and

Re: [ccp4bb] Generating parameters/cif files for macrocyclic ligands

2012-02-08 Thread Joel Tyndall
Hi Garib, Thanks for that (and thanks Herman). How do I declare a non-natural amino acid a peptide? My ligand contains two peptidic cycles (non-N to C) where the side chains are cyclised. I think I'll be able to use several linbk records for the connections but the non-natural amino acid are

Re: [ccp4bb] Dye for protein affinity measurement

2012-02-08 Thread Vandana Kukshal
Hi, - If ur protein is making strong complex then You can run Native page with increasing concentration of your inhibitor peptide and decrease in complex band intensity will show you competitive binding of your inhibitor to proteins. - You can do ELISA... by coating one of

Re: [ccp4bb] Collecting small-molecule diffraction on a Macromolecular xtallography beam line

2012-02-08 Thread Kay Diederichs
Hi Giorgio, some XDS-related hints can be found at http://strucbio.biologie.uni-konstanz.de/xdswiki/index.php/Small_molecules which I renamed to Difficult datasets since some of the suggestions also apply to those. What is lacking in that article is that you really should specify