Re: [ccp4bb] Transfer Rfree flag

2009-01-29 Thread David Cobessi
riya doreen wrote: Hello: Can someone tell me if there is a relatively straightforward way of transferring Free R flags between two CNS format reflection files ? Thanks Dear Riya, You can do it either by using CNS (merge.inp: keep the flags Rfree(A: dataset A), Fobs(B: dataset B) for examp

Re: [ccp4bb] [OFF TOPIC] his-tag doesn't bind

2009-01-29 Thread Chavas Leo
Dear Fred -- just to check... are you sure you have the His-tag? Might have been cleaved somehow? You might want to increase the number of His in the tag as well. HTH. -- Leo -- On 27 Jan 2009, at 21:00, Fred wrote: Hi ccp4 list, I am trying to purify a his-tag protein by metal affinity

Re: [ccp4bb] Problem running BALBES

2009-01-29 Thread Dr. F Long
Dear Jesse, The current version of BALBES can only find MR models of a protein complex from its own internal database. I guess in your case, BALBES did not find the complex models (assembly as shown on the balbes log file). What you expect BALBES to do is under developing within the new version of

Re: [ccp4bb] difficult MAD dataset

2009-01-29 Thread Eric Larson
Hi Allison, How sure are you of your spacegroup? Have you tried P212121? It is a much more common spacegroup. How did you look for your systematic absences? It is possible that the systematic absences are also present along the third axis even though all the reflections have not been measu

[ccp4bb] sparse matrix screen design

2009-01-29 Thread Jose Antonio Cuesta-Seijo
Hi all, a non-CCP4 question: Are there any good free programs for the design of one's own sparse matrix screens? I am looking for something in the lines of a set of mixtures of what gives you the best coverage of, say, seven variables with five states each in 96 experiments. Thanks, Jose

Re: [ccp4bb] difficult MAD dataset

2009-01-29 Thread Sanishvili, Ruslan
Hi Alison, At how many (and which) wavelengths were data collected? How much data at each wavelength? Which option was used in scaling with HKL2000 ("anomalous", "scale anomalous" or neither)? Any indication of radiation damage during data collection (i.e. disappearing higher resolution spots) or

Re: [ccp4bb] OT: VectorNTI alternatives

2009-01-29 Thread Francis E Reyes
Not sure if it's been mentioned, but I personally use EnzymeX(http://mekentosj.com/enzymex/ ) . Also, I find their PDF library organizer Papers (http://mekentosj.com/papers/ ) to be exceptional. Cheers FR On Jan 28, 2009, at 1:47 AM, Darren Hart wrote: Hello, After several years of offering

Re: [ccp4bb] mapping sequence conservation metrics on the B factor column ...

2009-01-29 Thread Link,Todd M
I like the consurf coloring scheme the best. I forget things so I had to write down the instructions which I copied off of some website which I can't seem to find at the moment. The other program is ESPript which I've also included my cheat sheet. Mapping conservation onto your structure (C

[ccp4bb] Transfer Rfree flag

2009-01-29 Thread riya doreen
Hello: Can someone tell me if there is a relatively straightforward way of transferring Free R flags between two CNS format reflection files ? Thanks

Re: [ccp4bb] mapping sequence conservation metrics on the B factor column ...

2009-01-29 Thread Anastassis Perrakis
Dear All, Thanks to all that replied in private and in the bb! Answers are and will be 'permanently' summarized at: http://strucbio.biologie.uni-konstanz.de/ccp4wiki/ http://strucbio.biologie.uni-konstanz.de/ccp4wiki/index.php/Mapping_sequence_alignment_to_a_structure (a nice opportunity to c

[ccp4bb] difficult MAD dataset

2009-01-29 Thread Alison Li
We recently collected a complete 2.5A MAD dataset. However, finding a solution has not been as straightfoward for reasons unclear to us. We would be grateful for any helpful advice or suggestions. The thin plate shaped crystal was grown from a relatively small protein (90 residues). The crysta

Re: [ccp4bb] mapping sequence conservation metrics on the B factor column ...

2009-01-29 Thread Mensur Dlakic
AL2CO ( http://www.ncbi.nlm.nih.gov/pubmed/11524371 ) may be what you need. It takes the multiple alignment (made by user, so it isn't a black box) that must contain the sequence of your structure, and maps the positional conservation in the B-factor column of the structure. To see whether this

Re: [ccp4bb] mapping sequence conservation metrics on the B factor column ...

2009-01-29 Thread Nathaniel Echols
On Thu, Jan 29, 2009 at 1:25 PM, Anastassis Perrakis wrote: > Dear all, > I was wondering what is the state of the art for this old dark art ... are > there any good servers / programs that allow to easily upload your own > sequence alignments or create a 'transparent' alignment (I want to see th

[ccp4bb] mapping sequence conservation metrics on the B factor column ...

2009-01-29 Thread Anastassis Perrakis
Dear all, I was wondering what is the state of the art for this old dark art ... are there any good servers / programs that allow to easily upload your own sequence alignments or create a 'transparent' alignment (I want to see the alignment first and not a total black box) and then allow yo

Re: [ccp4bb] X-ray photon correlation length

2009-01-29 Thread Ethan Merritt
On Thursday 29 January 2009 10:59:23 Bernhard Rupp wrote: > Ok, following seems to be correct: > > > > a) interaction length = mean free path : relevant for absorption > > b) correlation length = time correlation between photons : relevant for > multi-photon scattering > > c) c

Re: [ccp4bb] Problem running BALBES

2009-01-29 Thread Jesse Sundlov
Thank you Fei for your input. Your response inspired me and I found the error I was making (a poorly truncated PDB file). However I have another question regarding BALBES for the brains out there. As I mentioned before, I have a two protein complex with a nice homology model for Protein 1 and th

Re: [ccp4bb] X-ray photon correlation length

2009-01-29 Thread Bernhard Rupp
Ok, following seems to be correct: a) interaction length = mean free path : relevant for absorption b) correlation length = time correlation between photons : relevant for multi-photon scattering c) coherence length = longitudinal coherence length : relevant for single photon s

Re: [ccp4bb] X-ray photon correlation length

2009-01-29 Thread Nave, C (Colin)
Bernard I guess this came from "Aren't detwinning methods appropriate only in the case of true twin domains which are larger than the X-ray photon correlation length in order for the assumption to be valid that |F|^2 from each domain can be summed? This wouldn't give rise to the apparent 'diffuse s

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Jacob Keller
So it would seem that the five-fold periodicity in the spot intensities along the long axis is probably due to a short-range, 34 Ang pseudo-repeat (the decamer) along the true 170 Ang cell axis (170 = 34 x 5). I do not think that the streaks are helical layer lines, because the spacing on the

Re: [ccp4bb] X-ray photon correlation length

2009-01-29 Thread V. Nagarajan
>From memory, correlation length is the length during which the phase of the electric field is preserved. It's typically computed by applying time (pulse width)- frequency (converted to length) uncertainty principle. V. Nagarajan JAN Scientific, Inc. -Original Message- From: CCP4 bulletin

[ccp4bb] X-ray photon correlation length

2009-01-29 Thread Bernhard Rupp
I always wondered - how is the X-ray photon correlation length defined and where do I find it? This is not the interaction length, I assume. So, to the physicists: How large is the 'X-ray photon correlation length' for a given wavelength in a given material? I had the impression that

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Ian J. Tickle
<6d56f0ec21490b4db31a8ff1f0cb2914014ce...@ffpw10.f2.enterprise> <4981d8a7.6000...@gmail.com> From: "Ian Tickle" To: =?iso-8859-1?Q?Andreas_Förster?= , Cc: Return-Path: i.tic...@astex-therapeutics.com X-OriginalArrivalTime: 29 Jan 2009 16:27:43.0581 (UTC) FILETIME=[831110D0:0

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Andreas Förster
Ian and Herman, does one want to convolute the electron density at all? I was under the impression that current thinking favors convolution of the model instead, i.e. placing both the helices in both orientations at partial occupancy and letting the refinement program figure things out? An

Re: [ccp4bb] Fobs - Fobs

2009-01-29 Thread Ian Tickle
Rana, to a large extent this depends on what you what to do with the delta-F's afterwards (you didn't say). If all you want to do is calculate a map, Patterson or Fourier, (which is probably what we do most of the time with delta-F's) then you don't need to calculate the difference as a separate s

Re: [ccp4bb] Fobs - Fobs

2009-01-29 Thread Adam Ralph
You can use the CCP4 program sftools. You will need to use the program twice if you want to keep the differences positive ie F1 - F2 if F1>F2 and F2 - F1 if F2>F1 Adam On Thu, 29 Jan 2009, Rana Refaey wrote: > > Hi, > > I was wondering if anyone knows what programme I need to use to

Re: [ccp4bb] Fobs - Fobs

2009-01-29 Thread Bart Hazes
Hi Rana, You probably have multiple options suggested to you. One is sftools using the CALC command. If the subtraction includes a phase then sftools can also do the calculation on the full structure factor. Plain subtraction of amplitudes ensuring the result is >= 0 READ yourfile.mtz CALC

[ccp4bb] Fobs - Fobs

2009-01-29 Thread Rana Refaey
Hi, I was wondering if anyone knows what programme I need to use to subtract the Fobs of two different crystals from each other. Regards, Rana _ Invite your mail contacts to join your friends list with Windows Live Spaces. It's e

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Tommi Kajander
For this discussion another relevant reference might be: The 1.8 A crystal structure of a statically disordered 17 base-pair RNA duplex: principles of RNA crystal packing and its effect on nucleic acid structure. Shah SA, Brunger AT. J Mol Biol. 1999 Jan 29;285(4):1577-88. -tommi On Jan 2

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Herman . Schreuder
Dear Ian and Margriet, You are right, the correction needs to be done on F, not on |F|^2. If I recall correctly (I did not do it myself), the assumption was that Fobs = 0.5*Fobs(A) + 0.5*Fobs(B), so Fcorrected(A) = 2*Fobs - Fcalc(B) where A and B are the two orientations. Since one does not ha

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Ian Tickle
Hi Herman Aren't detwinning methods appropriate only in the case of true twin domains which are larger than the X-ray photon correlation length in order for the assumption to be valid that |F|^2 from each domain can be summed? This wouldn't give rise to the apparent 'diffuse scatter' phenomeno

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Herman . Schreuder
Dear Margriet, >From your description and what James Holton wrote, it seems that you have 2 >types of unit cells: A: with the "sense" strand in position 1 and the "antisense" strand in position 2 B: with the "antisense" strand in position 1 and the "sense" strand in position 2 If the crystal

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Mark J. van Raaij
The 34-34-34 cell does not predict all the spots, does it? from the diffraction pattern it seems only the 34-34-170 or 34-34-340 cell can predict all spots, so the structure should be solved in the one that predicts all spots. The procedure I would use is to take a 180º dataset, sacrificing so

Re: [ccp4bb] small lines in diffraction pattern

2009-01-29 Thread Nave, C (Colin)
Hi Nice of Jacob to mention the paper below but I don't think it is relevant to these patterns (well it might not be relevant to anything!). I think James has given the most likely explanation. The AB type stacking disorder he mentioned is similar to the type in the paper I referenced. I think Jam

Re: [ccp4bb] Small lines in diffraction pattern (more info)

2009-01-29 Thread Margriet Ovaere
Dear all, There were some comments about detector issues, but these can be ruled out, to my opinion, since the lines appeared on different beamlines. Default settings of mosflm (spot picking) finds the cell 34 34 34 90 90 90 (pointless indicating P41212) Structure was solved by SAD ph

Re: [ccp4bb] small lines in diffraction pattern

2009-01-29 Thread Bram Schierbeek
Hi Stephan, If there were overflows on the detector, which cause lines due to the spill over of the wells of the CCD, the lines would be visible in the readout direction of the CCD detector, which generally is from bottom to top or top to bottom. You can also see this with your own (pocket) c