Re: [ccp4bb] Choosing MR solutions in the case of perfect twinning with P41212?

2009-02-09 Thread Eleanor Dodson
Points to think about. 1) Do your data statistics indicate twinning - if they dont iyt is mst unlikely to be present Look at output of truncate ( new Ctruncate is better) Get phenix xtriage report.. 2) SAD phasing - I presume you knw it is P41212 and not P43212? 3) Going to a lower

Re: [ccp4bb] PHIDM AND FOMDM from DM

2009-02-09 Thread Eleanor Dodson
Xie Jiabao wrote: Dear all, I am using the density modification tool in ccp4 to generate improved phases for/from my model. I find that the electron density map I generate using Fobs, and density modified phases (PHIDM) are not the same as that generated using Fobs, phicalc (original

Re: [ccp4bb] refinment of mir anomalous data in MLPHARE

2009-02-09 Thread Eleanor Dodson
What are you assigning as FP and FPH? Can you send the complete command script? You have set a real occupacy to 1.0 which is not appropriate if FP and FPH are equal - it should be 0.000 But I await you complete script.. Eleanor Alpharyun Ni wrote: Hi everyone! I have a problem when I use

[ccp4bb] Off topic: 182 kDa protein is too large to crystallize

2009-02-09 Thread Marek Frischerkase
Dear all, I´m new in the field of crystallography. So please excuse my first question is off topic. I´m trying to purify a 182 kDa his-tagged bacterial enzyme. The expression in E. coli works quite well. After Ni-NTA the protein isn´t pure enough at all, so I tried several gelfiltration columns,

Re: [ccp4bb] Off topic: 182 kDa protein is too large to crystallize

2009-02-09 Thread Tim Gruene
Hi, 182kDa is large I'd say, but not too large for crystallisation. Since you are using a Ni-column anyway you could re-clone it with a His-tag that is cleavable by an enzyme (TeV, FactorX,... - I am a little out of date about which enzyme is the most favoured on nowadays). This would add

[ccp4bb] Getting Molprobity to run using WinCoot

2009-02-09 Thread ANDY DODDS
Dear all, I am trying to use the molprobity server with WinCoot 0.6-pre-1. I have followed the instructions here http://www.ysbl.york.ac.uk/~lohkamp/coot/wincoot-faq.html and believe I have put probe and reduce into the right places and pointed to them in the coot.py script. however, when I

Re: [ccp4bb] Off topic: 182 kDa protein is too large to crystallize

2009-02-09 Thread Magnus Alphey
Hi Marek, I agree with Tim. 182kDa is certainly not too large for crystallization. As for purification . Have you tried different buffer conditions for your Ni-NTA purification ? Adjusting the pH or salt component may improve the purification sufficiently. You could try changing the salt

Re: [ccp4bb] Getting Molprobity to run using WinCoot

2009-02-09 Thread bernhard
Hi Andy, where shall I start? 1.) Where is your probe.exe and reduce.exe? These should either be in your global PATH or in driveletter:\YourWinCootDirectory\bin. 2.) if you want to point to specific probe/reduce.exe files. These should be given in the .(dot)coot.py file (which in WinCoot is

Re: [ccp4bb] Off topic: 182 kDa protein is too large to crystallize

2009-02-09 Thread artem
Hello Marek, 182 kDa protein is nothing special - unless it has huge areas of disorder, membrane-association domains, coiled coils, or something like that. Much larger proteins and protein complexes have been successfully crystallized. With respect to purification - this is where you may want to

[ccp4bb] Off-topic: Open Source / Freeware Binding Curve Fitting Software

2009-02-09 Thread Jacob Keller
Hello All, can anyone recommend a nice, free software package for analyzing binding curves? The application I have in mind is fluorescence polarization studies between a FITC-peptide and a protein, for which I already seem to have good data. Thanks in advance, Jacob Keller

Re: [ccp4bb] TLS Create/Edit module error erases project folder

2009-02-09 Thread Michael Jackson
The folder unfortunately is gone.  I played with this more and it seems that not only does the TLS Create/Edit module have this error, the ccp4mg module does as well.  If I abort the process to remove the directory the project file and contents then are removed regardless of input but the

Re: [ccp4bb] Off-topic: Open Source / Freeware Binding Curve Fitting Software

2009-02-09 Thread Luke Kontogiannis
I have used qtiplot to fit nmr titration curves. http://soft.proindependent.com/qtiplot.html Another open-source app for data analysis and plotting http://scigraphica.sourceforge.net/index.html I run ubuntu linux and they are both available in the ubuntu repositories. Luke Kontogiannis

Re: [ccp4bb] Off topic: Crystal degredation with age

2009-02-09 Thread Roberto Steiner
Hi Ed, A bit late on the subject I have collected atomic resolution data (around 0.97A) on both bovine and porcine phospholipase A2 crystals which at the time of data collection were between 10-16 years old. Crystallization setup was liquid-liquid diffusion in glass capillaries.

[ccp4bb] protocol for harvesting proteins from bacterial periplasmic space

2009-02-09 Thread Matt Colins
Dear all, I plan to prepare a protein fused to pelB signal peptide and secreted to bacterial periplasmic space. Does anyone have a detailed protocol for harvesting the protein from bacterial periplasmic space? The protein needs to be in the native state and will be purified on a nickel column.

Re: [ccp4bb] Off-topic: Open Source / Freeware Binding Curve Fitting Software

2009-02-09 Thread Donnie Berkholz
On 10:43 Mon 09 Feb , Jacob Keller wrote: can anyone recommend a nice, free software package for analyzing binding curves? The application I have in mind is fluorescence polarization studies between a FITC-peptide and a protein, for which I already seem to have good data. Try fityk

[ccp4bb] postdoctoral fellow in membrane protein structure

2009-02-09 Thread Joanne Lemieux
Applications are invited for a postdoctoral position to work on the structure determination of rhomboid intramembrane proteases critical in cell signaling pathways. These proteases have been linked to human disorders such as hereditary blindness and breast cancer. Our aim is to understand

[ccp4bb] Se oxidation

2009-02-09 Thread aka akaka
Dear AllI would like to know whether oxidation of Se entails any problem for SAD or MAD experiments and/ or how to resolve it. Cannot use DTT or reducing agents in my protein (extracellular and disulphide bonds are important).ThanksDr. R.DepetrisWeill Cornell Medical College

Re: [ccp4bb] Se oxidation

2009-02-09 Thread Van Den Berg, Bert
Hi, I wouldn't worry about Se oxidation. In principle having a mix of oxidized/reduced seleniums is unfavorable, as you'll have less signal at the edge (broadening). However, all-oxidized Se apparently makes things better (sharper and more intense peak; I forgot the reference, i think it may

Re: [ccp4bb] Se oxidation

2009-02-09 Thread Michael Hothorn
Hi, I wouldn't bother either. I once phased a structure based on about 160 oxidized Se in the AU (Hothorn et al., JBC, 2006). Just make sure that most of them are oxidized and do a proper absorption scan. best Michael aka akaka wrote: Dear All I would like to know whether oxidation of Se

Re: [ccp4bb] Se oxidation

2009-02-09 Thread Pascal Egea
Hi,I believe it is not important as long as you run a proper scan of the crystal. Both forms will allow proper phasing. This is very well described in a paper from Thomazeau et al. here is the reference MAD on threonine synthase: the phasing power of oxidized selenomethionine. Acta Crystallogr D

Re: [ccp4bb] protocol for harvesting proteins from bacterial periplasmic space

2009-02-09 Thread Zhijie Li
Hi Matt, Why not check the NEB pMal system manual (http://www.neb.com/nebecomm/ManualFiles/manualE8000.pdf). It has a good cold osmotic shock protocol that I've been using for my periplasmic MBP fusions. Zhijie - Original Message - From: Matt Colins matt.colins2...@yahoo.com To:

Re: [ccp4bb] protocol for harvesting proteins from bacterial periplasmic space

2009-02-09 Thread Artem Evdokimov
http://www.sciencedirect.com/science?_ob=ArticleURL_udi=B6V5N-4C8PFBS-2_us er=10_rdoc=1_fmt=_orig=search_sort=dview=c_acct=C50221_version=1 _urlVersion=0_userid=10md5=aee9aceae8dfa17b363ee2ec634debb0 Osmotic shock is OK, or you can try chlorophorm disruption. You can Google for either to find