[ccp4bb] Solving the structure

2011-06-24 Thread mullapudi edukondalu
Dear Members, I have my first data set on one of my protein crystals, that diffract to 2.7 A, and the space group is I222. According to Mathews coefficient, there should be 4 molecules in the asymmetric unit. But, when I run molecular replacement programme it found only 3, and the crystal

Re: [ccp4bb] Solving the structure

2011-06-24 Thread Phil Evans
You do need to try space group I21 21 21 as well as these two space groups are indistinguishable from systematic absences Phil On 24 Jun 2011, at 08:50, mullapudi edukondalu wrote: Dear Members, I have my first data set on one of my protein crystals, that diffract to 2.7 A, and the

Re: [ccp4bb] Convert .cif to mtz

2011-06-24 Thread Phil Evans
The preferred general route into CCP4 for unmerged data for scaling and merging (if that is what you want to do) is through Pointless into Scala (or in future Aimless as a Scala replacement, or the future merged Pointless/Aimless (nameless)). At present Pointless will accept data from Mosflm,

[ccp4bb] Post-doc position in cryo-EM at Oxford

2011-06-24 Thread Robert Gilbert
A post-doctoral position, initially for two years, is open in the group of Robert Gilbert at the Division of Structural Biology, Oxford (http://www.strubi.ox.ac.uk). We are using both X-ray crystallography and cryo-EM to determine the structures of macromolecules and macromolecular complexes

Re: [ccp4bb] Solving the structure

2011-06-24 Thread Ed Pozharski
On Fri, 2011-06-24 at 09:50 +0200, mullapudi edukondalu wrote: Dear Members, I have my first data set on one of my protein crystals, that diffract to 2.7 A, and the space group is I222. According to Mathews coefficient, there should be 4 molecules in the asymmetric unit. But, when I run

Re: [ccp4bb] cif-file with restraints for HC4

2011-06-24 Thread Tim Gruene
Hello Marius, not being familiar with the chromophore, but could this be done by the prodrg-server? http://davapc1.bioch.dundee.ac.uk/prodrg/ Tim On Fri, Jun 24, 2011 at 12:06:54AM +0200, marius.schm...@ph.tum.de wrote: is there someone out there who worked out a cif-file WITH restraints

Re: [ccp4bb] Solving the structure

2011-06-24 Thread Roger Rowlett
You should also search in I212121, an alternative space group. If you have a reasonable solution, packing should be sensible. Matthews coefficient analysis is only a guide, as there is a distribution of solvent content values in typical protein crystals. We

Re: [ccp4bb] Convert .cif to mtz

2011-06-24 Thread Eric Larson
Hi Madhu, You don't need to use scala, d*trek can do the job as well. The easiest thing to do is to continue with d*trek to scale and merge your data and then input this scaled and merged file into Dtrek2mtz. Eric Eric T. Larson, PhD Biomolecular Structure

Re: [ccp4bb] Y-Chi2 running out of chart

2011-06-24 Thread Shiva Bhowmik
Hi Bie, Curious to know what are the cell parameters obtained after scaling? You mention observing perfect Chi2 statistics with lysozyme crystals. But are you observing the same Chi2 statisctis with the crystal that yielded unusual Y-Chi2 if you collect another dataset. If there is a consistency

Re: [ccp4bb] How to get rid of Tubulin derived from insect cell expression

2011-06-24 Thread Shiva Bhowmik
Amonium sulfate precipitation? Considering the fact that you tried to seperate tubulin contamination both by charge and mass difference amonium sulfate pption may work. Shiva On Thu, Jun 23, 2011 at 4:05 AM, Seungil Han shan06...@gmail.com wrote: All, I am sorry that this is off topic. My

[ccp4bb] Position available with Rigaku - Application Scientist in Life Sciences Division - The Woodlands, TX

2011-06-24 Thread Angela Criswell
Rigaku has an immediate opening for a motivated application scientist to join the Life Sciences group in our North American headquarters, located in The Woodlands, TX. The candidate must have a PhD degree in a relevant field and have previous experience in structural biology X-ray

Re: [ccp4bb] Y-Chi2 running out of chart

2011-06-24 Thread Jim Pflugrath
Instead of an imperfect crystal, this can also occur if one chooses the wrong Bravais lattice type (or spacegroup) to integrate. For example, if you choose tetragonal when it is really orthorhombic with a ~ b, or if you choose orthorhombic and beta is 90.2, then you can see that trying to force

Re: [ccp4bb] How to get rid of Tubulin derived from insect cell expression

2011-06-24 Thread Jacob Keller
How about hydrophobic interaction chromatography? JPK On Fri, Jun 24, 2011 at 12:22 PM, Shiva Bhowmik gene1...@gmail.com wrote: Amonium sulfate precipitation? Considering the fact that you tried to seperate tubulin contamination both by charge and mass difference amonium sulfate pption may

[ccp4bb] Kd's in Crystals

2011-06-24 Thread Jacob Keller
Dear Crystallographers, what is the dogma with regard to affinities in crystals? For example, if I soak three crystals in 1pM, 1nM, and 1uM compound X, and they all show equivalent density, does that mean that the affinity is really better than 1pM, or is the crystal of such a high local

Re: [ccp4bb] How to get rid of Tubulin derived from insect cell expression

2011-06-24 Thread Artem Evdokimov
Hey :) Tubulin has high affinity towards colchicine. You may be able to subtract it via colchicine-agarose if you can get some, or have some of it made. Alternatively, merely adding colchicine may be enough to break the complex between tubulin and whatever it is you're purifying (is it a kinase

Re: [ccp4bb] Kd's in Crystals

2011-06-24 Thread Edward A. Berry
Jacob Keller wrote: Dear Crystallographers, what is the dogma with regard to affinities in crystals? For example, if I soak three crystals in 1pM, 1nM, and 1uM compound X, and they all show equivalent density, does that mean that the affinity is really better than 1pM, or is the crystal of such