- phenixbb - phenix-online.org

some sort of occupancy refinement
by Bryan W. Lepore 01 Jan '10

01 Jan '10

question is after the setup here : i have a ligand with multiple conformers. i gave each conformer a different chain label. refining occupancy for the overlapped parts kicks that part out of the density. i have remove_selection for the parts that are 1.0 and they seem OK. a single conformer stays in the density. i tried starting with and without site or occupancy refinement, no help. i do not want group occupancy refinement b/c some parts do not overlap - i.e. they "should" be occupancy 1.0 -- i tried it anyways with constrained_group =... to check. is the chain label an improper way to do this? -bryan p.s: Happy New Year with Blue Moon Eclipse (~10degW->180degE long. eastern HS)!

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high resolution Anomalous map
by vennila Natesan 01 Jan '10

01 Jan '10

Hello all... How do we create anomalous map using high resolution reflections? For example, if we have 2.2A resolution data (i.e 20-2.2A), i want to know how to create the anomalous map for the same dataset but from 2.4-2.2A resolution range. Vennila.

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phenix.refine change: support for residues on symmetry elements
by Ralf W. Grosse-Kunstleve 28 Dec '09

28 Dec '09

The current development version of phenix.refine (dev-268 or later) supports residues located on symmetry elements, e.g. SO4 on a three-fold axis. phenix.refine now computes structure factors slightly differently compared to older versions. The new rules are: - Atoms with occupancy == 1 are subject to automatic handling of the symmetry. Example: An atom near a three-fold axis (distance to symmetry copy <= 0.5 A) is moved onto the axis and constrained in refinement to stay on the axis. The "special position factor" (1/3 is this case) is taken into account internally. The factor does not appear in the occupancy. - Atoms with occupancy != 1 are assumed to take the special position factor into account in the occupancy. Automatic handling of the symmetry is turned off. Example: A disordered SO4 molecule near a three-fold axis should have occupancies of 0.33 for all atoms. - If all atoms in a residue have occupancies != 1, all nonbonded symmetry interactions between the atoms in the residue are disabled. These three rules are meant - to bring phenix.refine in line with other programs and the PDB. - "to do the right thing" in most cases without manual intervention. Please let me know if you see problems with the new way phenix.refine uses occupancies to determine special position constraints and exclusions for nonbonded symmetry interactions. Does anyone need atoms with partial occupancies but constrained to stay on a symmetry axis during refinement? Ralf

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Re: [phenixbb] Phaser SAD question
by Kitty Pattridge 25 Dec '09

25 Dec '09

"Randy J. Read" <rjr27(a)cam.ac.uk> wrote: >Dear Peter, > >I'm interested in your observation that you get better signal from an >anomalous difference map computed with density-modified phases than you get >with an LLG map using the MR model. Presumably the density modification >just started from the model phases as well? We've never tried that, so >we'll have to look into that. Unfortunately, you can't at the moment start >the LLG completion with a "model" specified through structure factors, >though this is on our to-do list. > >With the MR+SAD option, because it is iterative, there are sites found in >subsequent cycles (where the information from some of the anomalous >scatterers has become available) and you end up with a set of reliable >sites that can be significantly larger than the set obtained from the first >LLG map. Does your anomalous difference Fourier with density modified >phases give you a larger apparently reliable substructure than the >iterative completion? You could use phenix.emma to compare the two >substructures and see how much they have in common. > >You can indeed give Phaser the set of sites that you got from the anomalous >difference map. One way to choose the cutoff would be to see how deep the >deepest hole is (i.e. how many standard deviations the map goes in the >negative direction), and choose a larger number in the positive direction. >Or you could just use the peaks above 6-7 sigma. > >I'd be interested in hearing how you get on with this approach, off-line if >you prefer. > >Good luck and Happy Christmas! > >Randy Read > >On Dec 24 2009, Peter Grey wrote: > >>Dear Phenix Experts, >> >>I use the SAD+MR option in Phenix. The ASU is huge and the number of >>scatterres is in the few hundreds range. I try to minimize the number of >>runs of Phaser SAD+MR since they take long time on my computer and would >>appreciate your insight regarding the following : >> >> - I noticed that I get much higher signal and much larger number of sites >> if I use density modified phases to calculate the anomalous difference >> map. Is it possible to input these phases instead of the model to Phaser >> ? >> >> - If not, do you recommend providing Phaser with the list of sites found >> in this difference anomalous map. Should such a list include only the >> sites you can be sure of (say above 7 sigma) or all possible sites (say >> above 5 sigma) ? >> >> - Should I use the (peak height)/(sigma of map) as the first estimate of >> occupancy ? if so do I have to normalize it (strongest site has occupancy >> of 1) or can I leave the height/sigma values as they are ? >> >> >>Many thanks, >> >>Peter. >> > >_______________________________________________ >phenixbb mailing list >phenixbb(a)phenix-online.org >http://phenix-online.org/mailman/listinfo/phenixbb > >

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Re: [phenixbb] Phaser SAD question
by Kitty Pattridge 25 Dec '09

25 Dec '09

"Randy J. Read" <rjr27(a)cam.ac.uk> wrote: >Dear Peter, > >I'm interested in your observation that you get better signal from an >anomalous difference map computed with density-modified phases than you get >with an LLG map using the MR model. Presumably the density modification >just started from the model phases as well? We've never tried that, so >we'll have to look into that. Unfortunately, you can't at the moment start >the LLG completion with a "model" specified through structure factors, >though this is on our to-do list. > >With the MR+SAD option, because it is iterative, there are sites found in >subsequent cycles (where the information from some of the anomalous >scatterers has become available) and you end up with a set of reliable >sites that can be significantly larger than the set obtained from the first >LLG map. Does your anomalous difference Fourier with density modified >phases give you a larger apparently reliable substructure than the >iterative completion? You could use phenix.emma to compare the two >substructures and see how much they have in common. > >You can indeed give Phaser the set of sites that you got from the anomalous >difference map. One way to choose the cutoff would be to see how deep the >deepest hole is (i.e. how many standard deviations the map goes in the >negative direction), and choose a larger number in the positive direction. >Or you could just use the peaks above 6-7 sigma. > >I'd be interested in hearing how you get on with this approach, off-line if >you prefer. > >Good luck and Happy Christmas! > >Randy Read > >On Dec 24 2009, Peter Grey wrote: > >>Dear Phenix Experts, >> >>I use the SAD+MR option in Phenix. The ASU is huge and the number of >>scatterres is in the few hundreds range. I try to minimize the number of >>runs of Phaser SAD+MR since they take long time on my computer and would >>appreciate your insight regarding the following : >> >> - I noticed that I get much higher signal and much larger number of sites >> if I use density modified phases to calculate the anomalous difference >> map. Is it possible to input these phases instead of the model to Phaser >> ? >> >> - If not, do you recommend providing Phaser with the list of sites found >> in this difference anomalous map. Should such a list include only the >> sites you can be sure of (say above 7 sigma) or all possible sites (say >> above 5 sigma) ? >> >> - Should I use the (peak height)/(sigma of map) as the first estimate of >> occupancy ? if so do I have to normalize it (strongest site has occupancy >> of 1) or can I leave the height/sigma values as they are ? >> >> >>Many thanks, >> >>Peter. >> > >_______________________________________________ >phenixbb mailing list >phenixbb(a)phenix-online.org >http://phenix-online.org/mailman/listinfo/phenixbb > >

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Phaser SAD question
by Peter Grey 24 Dec '09

24 Dec '09

Dear Phenix Experts, I use the SAD+MR option in Phenix. The ASU is huge and the number of scatterres is in the few hundreds range. I try to minimize the number of runs of Phaser SAD+MR since they take long time on my computer and would appreciate your insight regarding the following : - I noticed that I get much higher signal and much larger number of sites if I use density modified phases to calculate the anomalous difference map. Is it possible to input these phases instead of the model to Phaser ? - If not, do you recommend providing Phaser with the list of sites found in this difference anomalous map. Should such a list include only the sites you can be sure of (say above 7 sigma) or all possible sites (say above 5 sigma) ? - Should I use the (peak height)/(sigma of map) as the first estimate of occupancy ? if so do I have to normalize it (strongest site has occupancy of 1) or can I leave the height/sigma values as they are ? Many thanks, Peter.

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Re: [phenixbb] phenix GUI freezing during refinement and file naming issues
by John Berrisford 24 Dec '09

24 Dec '09

Dear all. When the GUI freezes on me its a complete freeze with no pop up dialog boxes. This means the job history is not recorded and no results are recorded in the GUI. I'm not sure if this is screensaver or desktop switching related - it only seems to happen randomly - mostly when running long jobs where nothing much happens on the screen, in my experience. I'm also using an nVidia card and an upto date version of the X-server (on my ubuntu 9.10 box). I agree this is a minor issue compared to having a great program which works well. But it does mean that if its easier to use a command line all your hard work with the GUI (and its enhancements) will go to waste... John -- John Berrisford Medical Research Council Mitochondrial Biology Unit Wellcome Trust / MRC Building Hills Road Cambridge CB2 0XY WEB: www.mrc-mbu.cam.ac.uk TEL: +44 (01223) 252918

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rotational pseudosymmetry in P61?
by Gabriela Guédez R. 24 Dec '09

24 Dec '09

Hi all, how could i determine the r.m.s.d. and matrix of the NCS operator that relates two molecules in the asymmetric unit in P61? i would like to know whether there is rotational pseudosymmetry in the crystal because i see peaks for two molecules in the kappa=180º SR map. Thanks a lot!

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Autosol problem: Failed to carry out Autosol_scale_and_analyze_mad
by Zheng Zhou 23 Dec '09

23 Dec '09

Dear all I installed phenix nightly builds, dev-256. I have solved structures using molecular replacement. Phenix.refine runs smoothly. Thanks for your great work. When I run some test data using autosol, I met the following error message: ******************************************************************************** Failed to carry out AutoSol_scale_and_analyze_mad: None of the solve versions worked See overall log file and also solve log file (in AutoSol_run_1_/LAST.LOG) ******************************************************************************** The LAST.LOG appears to be empty. I also run the phenix.solve command. Here is the output: ********************************************************************************************* $ phenix.solve binary=/usr/local/phenix-dev-254/build/intel-linux-2.6/solve_resolve/exe/solve SOLVEDIR=/usr/local/phenix-dev-254/solve_resolve/ext_ref_files SYMOP=/usr/local/phenix-dev-254/solve_resolve/ext_ref_files/symop.lib SYMINFO=/usr/local/phenix-dev-254/solve_resolve/ext_ref_files/syminfo.lib CCP4_OPEN=UNKNOWN SOLVE_RESOLVE_MALLOC_MAX=7.48024e+09 /usr/local/phenix-dev-254/build/intel-linux-2.6/solve_resolve/exe/solve: error while loading shared libraries: /usr/local/phenix-dev-254/build/intel-linux-2.6/lib/libimf.so: cannot restore segment prot after reloc: Permission denied ***************************************************************************************************** The libimf.so file is there. I run phenix.solve as superuser, but I still have the same problem. Thanks for your help. Best, Joe

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phenix GUI freezing during refinement and file naming issues
by John Berrisford 23 Dec '09

23 Dec '09

Dear all I've recently been having a few problems with the new phenix GUI freezing during refinement runs on several different systems, most often when I try and do something different on the computer which puts the GUI in the background or on a different desktop. I've seen this problem when running a local copy of phenix on a ubuntu 9.10 system or when running the GUI remotely on a mac connected to our Centos linux cluster. When I switch to a different desktop to get on with doing something else (refine jobs can take a long time) the GUI freezes - although the underlying task runs correctly. The only way out of this problem is to force quit the GUI and then restart it. However, this means that the task isn't recorded in my history and all settings used to run the job are lost from the GUI - the parameter file to run the job does exist though. This also means I lose all the nice molprobibity connections to coot which are really useful. Also if I try to run phenix on the Centos linux cluster when running a local windows system the GUI is so sllloooowwww whenever the GUI tries to open a new window that its unsuable. Has anyone else seen these problems and know a cure? If I run phenix locally on a mac I don't seem to have this problem, but it is nice to run the refine job on our linux cluster so that I can get on with doing something else without it slowing down my mac. On another note, when running phenix refine from the GUI it nicely puts all the files in a folder called "Refine_1" etc... with the number incrementing with each run. So, why are the pdb and mtz file always called "refine_1..." not "refine_2 etc... to match the folder name? This would help with keeping track of files during itterative refinement and model building. It would also stop the problem of having lots of files called "refine_1" loaded into coot when I try to compare models from different refine runs. It would also be useful to be able to be able to add a prefix to the file name / folder name / job name in the GUI so that I could distinguish between different refinement experiments. This is easy to do on the command line.... Thanks and merry christmas John -- John Berrisford Medical Research Council Mitochondrial Biology Unit Wellcome Trust / MRC Building Hills Road Cambridge CB2 0XY WEB: www.mrc-mbu.cam.ac.uk TEL: +44 (01223) 252918

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