[ccp4bb] Postdoctoral Fellow, Membrane protein structure at the ESRF

2009-02-06 Thread Matthew BOWLER
Dear CCP4 users, We have an opening at the ESRF Macromolecular crystallography group (http://www.esrf.fr/UsersAndScience/Experiments/MX) for a Post-Doc to work on *the role of membrane proteins in the resistance of */Deinococcus radiodurans/* to extreme conditions (see advert below). The

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

2009-02-06 Thread Prof. Joel L. Sussman
As written in Jovine, L., Djordjevic, S. Rhodes, D. (2000). “The crystal structure of yeast phenylalanine tRNA at 2.0 A resolution: cleavage by Mg(2+) in 15-year old crystals” J Mol Biol 301, 401-414. Furthermore, the possibility of a Mg2+-catalysed cleavage of the phosphodiester bond

Re: [ccp4bb] PHIDM AND FOMDM from DM

2009-02-06 Thread Clemens Vonrhein
Dear Xie, you need to use the right columns for calculating maps. From your description it seems you could do the following in FFT: a) map after density modification: F1=Fobs PHI=PHIDM W=FOMDM or (DM should write out these columns as well): F1=FDM PHI=PHIDM See:

Re: [ccp4bb] comparison of maps, intensities and other basics

2009-02-06 Thread Peter Schmidtke
Thank you very much for this clear and long answer, Dale. You gave me exactly the information I needed. Thanks again having taken the time to answer to my questions. Cheers. Peter On Thu, 5 Feb 2009 14:51:15 -0800, Dale Tronrud det...@uoxray.uoregon.edu wrote: A map file stores a density

[ccp4bb] Marie Curie Fellowship

2009-02-06 Thread Demetres D. Leonidas
Please find attached an advert for a short Marie-Curie fellowship at the National Hellenic Research Foundation, Athens, Greece. We seek to recruit a biology/biochemistry graduate, with not more than 4 years of research experience at post-graduate or equivalent level, who will be trained by

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

2009-02-06 Thread Brad Bennett
FWIW, many of the crystals used in classical neutron diffraction experiments were pretty elderly samples by the time data collection was initiated, partly to allow large crystals to grow ever larger, partly because of the mandatory deuterium exchange process and partly because the experiments

[ccp4bb] Rigid body refinement as last refinement?

2009-02-06 Thread Andy Millston
I am told by a mentor that rigid body refinement should never be the last refinement before submission to pdb. Any idea why? Structures in which every round of retrained refinement messes up a conformation, is there any alternative to not using rigid body refinement? Andy

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

2009-02-06 Thread Michael Jackson
Hello,   I was using the TLS Create/Edit module to create a TLS file from scratch. In the module I ran it once but wanted to change some parameters.  While I had the module interface still open, I selected to delete the TLS project entry just made in the list of jobs.  When I did this I did not

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

2009-02-06 Thread Edward A. Berry
For a counterexample, from Iwata's group, Horsefield et al. Succinate: quinone oxidoreductase Acta. Cryst.(2003). D59, 600-602: It proved critical to freeze the crystals within 72 h of crystallization set-up. Crystals that were frozen after this time limit showed no diffraction. This

Re: [ccp4bb] Rigid body refinement as last refinement?

2009-02-06 Thread Andy Millston
Thank you for your responses. Restrained refinement does a good job at refining most of the structure except a small region with poor density. Every time I refine it, it puts this region completely out of the map. It doesn't have much effect on overall geometrical factors as its a very small

Re: [ccp4bb] Rigid body refinement as last refinement?

2009-02-06 Thread William G. Scott
Hi Andy: Just be very careful of special pleading type arguments. I really think this is trying to tell you something, along with the Ramachandran plot. On a more practical level, the PDB will flag it when you try to deposit it. There is something wrong. It might be worth making a

Re: [ccp4bb] Rigid body refinement as last refinement?

2009-02-06 Thread Clemens Vonrhein
Hi, On Fri, Feb 06, 2009 at 08:13:29AM -0800, Andy Millston wrote: Restrained refinement does a good job at refining most of the structure except a small region with poor density. Every time I refine it, it puts this region completely out of the map. Do you mean: a) after restrained

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

2009-02-06 Thread Engin Ozkan
I have to second that. I recently had crystals that will only grow after seeding and will live for exactly five days. On the sixth day, the same drop will have tracks of dissolved crystals left in every drop: they almost look like tire tracks. The crystals frozen on the fifth day diffract to

[ccp4bb] SLS non-PX Beamlines: Call for Proposals will be launched on 8 February

2009-02-06 Thread Stefan Mueller
Dear SLS users, Next call for proposals for the non-PX beamlines of the Swiss Light Source, SLS will be launched on the 8th of February, 2009. Deadline for proposal submission: Sunday, March 15, 2009 Submission: All submissions will be handled by the SLS Digital Users Office (DUO)

[ccp4bb] Hi prep column from GE

2009-02-06 Thread Michael Colaneri
We have a hi prep SP column from GE. We try to load ~14 mg protein but all goes to FT. We lowered the pH and changed the buffer but no luck. We would appreciate all suggestions. Mike Colaneri