Re: [ccp4bb] popular piece on X-ray crystallography

2013-04-22 Thread Navdeep Sidhu
The cycles of accretion, nuclear interconversions and cooling of matter is far from complete but if we fast forward the universe by n billions of years, it's remarkable how much of it turns out to be crystalline. A bit like a crystallization trial at a cosmic scale. Does assume an

[ccp4bb] software molecular replacement

2013-04-22 Thread LISA
Hi all, There are so many software for MR, such as phaser, balbe,molrep, and amore. What is difference between them? Which one is powerful? Please give some comments for these software?Thank you. Sincerely, lisa

Re: [ccp4bb] software molecular replacement

2013-04-22 Thread Mark J van Raaij
Hi Lisa, I would start with learning AMoRe. It is relatively simple, runs fast and uses little memory, so you can experiment easily with lots of parameters. It is also relatively easy to modify the parameters, radii etc. and get a feel for which ones to use. If after a few days or weeks you

Re: [ccp4bb] xprep simulated powder diffraction

2013-04-22 Thread Tim Gruene
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Dear James, my guess is that xprep removes ( 0 0 0) for a better contrast, but I don't know for sure - George is going to tell you, I guess, because he will know ;-) The reason I answer is rather a comment: I would not call the tutorial you refer to

Re: [ccp4bb] software molecular replacement

2013-04-22 Thread Roger Rowlett
There are three general approaches to molecular replacement: 1. rotation-translation algorithms: these divide the 6-dimensional problem of placing a replacement model in the ASU into two sequential 3-parameter searches, which, if it works, converges more quickly than a 6-dimensional

[ccp4bb] Struther Arnott

2013-04-22 Thread James Naismith
Older members of the bulletin board will be sad to learn that Struther Arnott FRS, fibre diffractionist and biophysicist (as well as former St Andrews Principal) died on Saturday. Jim Naismith James H. Naismith FRSE FMedSci| naism...@st-andrews.ac.uk Professor of Chemical Biology

Re: [ccp4bb] Struther Arnott

2013-04-22 Thread Peter Moody
Sad news indeed, he mentored my mentors, His influence on crystallography (rather than fibre diffraction) in not always as well appreciated as it might be. Peter On 22 April 2013 14:44, James Naismith naism...@st-andrews.ac.uk wrote: Older members of the bulletin board will be sad to learn

[ccp4bb] Off topic: type X collagen

2013-04-22 Thread Rex Palmer
Does anyone have a nice graphic of type X collagen? Thanks in advance.   Rex Palmer http://www.bbk.ac.uk/biology/our-staff/emeritus-staff http://rexpalmer2010.homestead.com

[ccp4bb] cyclising proteins

2013-04-22 Thread Dean Derbyshire
Hi all, perhaps not the right forum but... ...is there a way in coot to make a lysine side-chain // carboxy-terminal iso-peptide bond? Cheers in advance Dean

[ccp4bb] gelification of a pure protein

2013-04-22 Thread Pascal Egea
Dear All, I am presently faced with a peculiar case in the lab. We are expressing a protein in E. coli and we are able to express it as a fusion protein without problems . Fusion cleavage goes well and the final product looks homogenous by size-exclusion chromatography with the expected molecular

Re: [ccp4bb] gelification of a pure protein

2013-04-22 Thread Mark van Raaij
reminds me of structure 1NEU, although here the gelation was reversible, see ref and abstract below - the paper has a photo of a tube of soluble protein and gelled protein we have also had a couple of cold-sensitive proteins in our hands, that precipitated at 4 degrees when concentrated, but

Re: [ccp4bb] Modelling Software for beta turn design

2013-04-22 Thread Joel Tyndall
Dear Wenzong, Could you provide a bit more details please? Do you simply require some visualisation tool e.g. pymol to superimpose your turn mimic on your protein/peptide structure or are you looking for more indepth modelling to say identify new scaffolds to build amino acid sidechains onto

Re: [ccp4bb] Modelling Software for beta turn design

2013-04-22 Thread Wenzong Li
I want to build the loop based on a computer screen against my peptide. Thanks Wenzong - Original Message - From: Joel Tyndall joel.tynd...@otago.ac.nz To: Wenzong Li wenzong...@cm.utexas.edu, CCP4BB@JISCMAIL.AC.UK Sent: Monday, April 22, 2013 6:10:09 PM Subject: RE: [ccp4bb] Modelling

Re: [ccp4bb] gelification of a pure protein

2013-04-22 Thread Michael Thompson
Does your protein have multiple exposed Cys residues? I have observed this before with a protein I worked with that had many exposed Cys residues. In my case I could add more DTT and minutes later the gel would be completely dissipated. My hand-wavy explanation was that the protein stays folded

Re: [ccp4bb] gelification of a pure protein [SEC=UNCLASSIFIED]

2013-04-22 Thread DUFF, Anthony
I have experienced a similar thing with lysozyme immediately forming a clear gel when attempting to dissolve at high concentration in D2O. The clear gel did not readily dissolve on dilution (in D2O) and I discarded it. I later made the sample by dissolving in H2O and dialysing to D2O.

Re: [ccp4bb] gelification of a pure protein

2013-04-22 Thread Pascal Egea
Thanks to All for the diligent answers to my query, The protein is not thermophilic and has only one cysteine. We are working in presence of freshly added reducing agent and glycerol to promote solubility (well kinda it seems). This is not an RNA or DNA binding protein and it has no

Re: [ccp4bb] Modelling Software for beta turn design

2013-04-22 Thread Pete Meyer
Wenzong, You may want to look at rosetta's design modules. Pete Wenzong Li wrote: I want to build the loop based on a computer screen against my peptide. Thanks Wenzong - Original Message - From: Joel Tyndall joel.tynd...@otago.ac.nz To: Wenzong Li wenzong...@cm.utexas.edu,

Re: [ccp4bb] gelification of a pure protein

2013-04-22 Thread Shane Caldwell
Hi Pascal, Your problem brings to mind this paper: FG-Rich Repeats of Nuclear Pore Proteins Form a Three-Dimensional Meshwork with Hydrogel-Like Properties Science 3 November 2006: 314 (5800), 815-817.[DOI: 10.1126/science.1132516] Of course, in that case, the gellation was deliberate, but

Re: [ccp4bb] Modelling Software for beta turn design

2013-04-22 Thread Joel Tyndall
Ahh Ok, now I see. I guess you need a search engine that idenitifies an antiparallel beta sheet with a turn. Whilst I don't know how to do it, maybe the pdb or epdb may do this or even modeller loop via accelrys interface Joel -Original Message- From: CCP4 bulletin board

[ccp4bb] Mutated biological binding interactions as crystal contacts

2013-04-22 Thread Owen Pornillos
Hi all - I am looking for examples of structures of protein-protein complexes (homo or hetero) wherein the crystallized proteins had mutations within their binding interfaces, and yet the same (weakened) interactions were still recapitulated in crystal contacts. Any leads would be much