Re: [ccp4bb] Deglycosylation enzymes

2010-07-09 Thread Shaun Lott
Or you could just bug me to find the PNGaseF expression plasmid that I should have in the freezer somewhere! LOO T., PATCHETT M. L., NORRIS G. E. LOTT J. S. “Using Secretion to Solve a Solubility Problem: High-yield Expression in E. coli and Purification of the Bacterial Glycoamidase PNGase

Re: [ccp4bb] How to make fft-map more physically meaningful?

2010-07-09 Thread Alexandre Urzhumtsev
Dear Hailiang, This apparently is not the real physics, since the electron density has to be positive everywhere (hope I am right). Yes, you are right when you are talking about the electron density. You are wrong when you are talking about a Fourier synthesis calculated always at a finite

[ccp4bb] 8th International NCCR Symposium on New Trends in Structural Biology

2010-07-09 Thread Patrick Sticher
Dear colleagues, we have the following announcements to make: 8th International NCCR Symposium on New Trends in Structural Biology 2 + 3 September 2010, ETH Zürich, Lecture Hall HG E7, Zürich, Switzerland For more

Re: [ccp4bb] How to make fft-map more physically meaningful?

2010-07-09 Thread Harry Powell
Hi Sacha is absolutely right here. This was made plain to me during a plenary session at the recent BCA meeting in Warwick, given by a powder (not protein) crystallographer - who was using histogram matching density modification, with negative densities; an expert in density modification in

Re: [ccp4bb] Beginning crystallography text

2010-07-09 Thread Nic Steussy
Stout and Jensen, "X-ray structure determination", 1989 Solid mid-level theory with practical examples. Most of the hardware discussed is very dates, but otherwise an excellent intermediate text. Nic out Bernhard Rupp wrote: The question of what textbook to use is very much context

Re: [ccp4bb] Question about R/Rfree value difference

2010-07-09 Thread Dirk Kostrewa
Hi Tom, very nice tool! It would be good to get numerical values of the plotted distributions as well, like mean, median, standard deviation and so on. Best regards, Dirk. Am 08.07.10 15:20, schrieb Tom Oldfield: Sampath With regard to your question on what sort of statistics you should

[ccp4bb] Fwd: postdocs

2010-07-09 Thread Schertler Gebhard
Prof. Gebhard Schertler Head of Biology and Chemistry Biomolecular Research Laboratory Paul Scherrer Institute Anfang der weitergeleiteten E-Mail: Von: Daniel Oprian opr...@brandeis.edu Datum: 8. Juli 2010 17:16:43 MESZ An: gebhard schertler gebhard.schert...@psi.ch Betreff: postdocs

[ccp4bb] Mysterious density

2010-07-09 Thread Nick Quade
Dear CCP4 community, I have solved the structure of a protein in complex with DNA. But, inside the protein there seems to be a ligand binding pocket with some strong density (*http://picasaweb.google.de/113264696790316881054/Desktop#). *The protein was in Tris buffer, with some NaCl, MgCl2

Re: [ccp4bb] Mysterious density

2010-07-09 Thread Paula Lario
Another thing to consider is alternate ligand conformation. The water density (elongated) and the pocket composition (aromatic) could result in two alternative binding orientations (of the buffer? I need 3D). I would play around with models to see if it fits the density. Paula Lario

Re: [ccp4bb] Mysterious density

2010-07-09 Thread Dale Tronrud
Cyclized DTT can look similar to this blob. Of course the sulfur atoms would make one end of the blob more dense than the other. Dale Tronrud On 07/09/10 05:12, Nick Quade wrote: Dear CCP4 community, I have solved the structure of a protein in complex with DNA. But, inside the protein

[ccp4bb] One PhD position and one Postdoc position available in structural virology

2010-07-09 Thread Frank Lee
(1) PhD position One PhD position is available in Dr. Fang Li's lab at the Department of Pharmacology, University of Minnesota Twin Cities. Research involves biochemical and structural studies on proteins that guide invasion and replication of important viral pathogens. Candidates should

[ccp4bb] oasis4 _ window or redhat x64 bit

2010-07-09 Thread venkat
Hi all I am trying to run oasis for my SAD data using dual space iteration. I am using ccp4-6.1.13 and seems it has the older gui and older oasis version 6.0. I downloaded the new oasis4 and ran the program with dual space iteraction option and end up in normal termination with out any

Re: [ccp4bb] How to make fft-map more physically meaningful?

2010-07-09 Thread Hailiang Zhang
Dear Sacha: Yes, I think Fourier synthesis at a finite resolution range will generate some negative, or more generally imaginary values in real space (hope I am right again:). For the imaginary values, I think the map should take the amplitude of it (maybe I am wrong). Do they normally make the

Re: [ccp4bb] How to make fft-map more physically meaningful?

2010-07-09 Thread James Holton
Uhh. No. You will only get imaginary electron density if your structure factors violate Friedel's law. I am not aware of map calculation codes that do this (on purpose). BTW, imaginary electrons are really just slow electrons that don't respond to the x-rays as fast as the average electron

[ccp4bb] Free mounting system ,Resolution improvement

2010-07-09 Thread Manoj Saxena
Hi, I am trying to find best methods for controlled crystal dehydration with an aim of improving diffraction resolution (currently at 9A).I have found few references and success stories about Free mounting system. I would be very grateful if you can share your personal experiences with Free

[ccp4bb] Re : Re: [ccp4bb] How to make fft-map more physically meaningful?

2010-07-09 Thread Alexandre OURJOUMTSEV
Dear Hailiang,As James said, the hermitian symmetry of Fourier coefficients, F(h)=F*(-h), that is known in diffraction theory as the Friedel's law, is an equivalent of the condition that the corresponding function (electron density) is a real function.I think if you need further information you

Re: [ccp4bb] Wilson B and Mean B factors

2010-07-09 Thread Peter Zwart
I've never looked at this statistics before, so I'm a bit surprised So am I ! - I was expecting a larger discrepancy between Wilson B and average B at low resolution. Although this is probably because PHENIX uses Peter Zwart's likelihood-based Wilson B estimation (Peter - what's the

[ccp4bb] Question about the MStats utiliy in UPPSALA-mapman

2010-07-09 Thread Hailiang Zhang
Hi, I am using the MStats utiliy in UPPSALA-mapman to compare the density inside and outside of the mask of the model (basically my target is to somehow quantify the level of noise outside the model mask). According to the instructions, I need to do: (1) MAPMAN re m1 in.map ccp4