- phenixbb - phenix-online.org

Post-doctoral Fellowships at the University of Texas
by Gabrielle Rudenko 04 Nov '13

04 Nov '13

*Macromolecular Crystallography, Biophysics and Biochemistry* Two post-doctoral fellowship positions are available at the University of Texas Medical Branch (UTMB) located in the greater Houston area in the research team of Dr. Gabrielle Rudenko. We study molecules that mediate the formation, maintenance and plasticity of synapses, the contact and communication point between neurons. Our proteins of interest organize and regulate protein interaction networks in the synaptic cleft and impact how neurons communicate with each other at synapses. Many of the proteins we study are implicated in neurological disease and serve as potential novel therapeutic targets. We are looking for highly motivated, enthusiastic, hard working individuals who are interested in combining the fields of structural biology and neuroscience. Research projects involve protein over-expression and purification, x-ray crystallography, biochemical and biophysical techniques, proteomics, chemical biology and in collaboration electron microscopy and NMR. Our laboratory is joining the endowed Sealy Center for Structural Biology and Molecular Biophysics and the Department of Pharmacology/Toxicology at UTMB. The Sealy Center provides access to exceptional facilities, training and experimental assistance. *X-ray facilities* include a high-brilliance FR-E Superbright x-ray generator, a Rigaku R-AXIS-IV dual 30cm Imaging Plate detector, a Bruker SMART 2K CCD and a Rigaku BioSAXS-1000 2D-Kratky camera (for solution scattering data). *Biophysics facilities* include equipment for analytical ultracentrifugation, fluorescence, MALDI-TOF mass spectrometry, dynamic light scattering, surface plasmon resonance, titration micro-calorimetry, and high throughput screening with the ThermoFluor HTS apparatus. In addition, the *Electron Microscopy facilities*house three modern JEOL cryo-electron microscopes (a 200 keV JEOL 2200FS cryo-EM with in-column electron energy filter and field emission gun, a 200 keV JEOL 2100 EM, and a 120 keV JEM1400 microscope) and the *NMR facilities*include three NMR spectrometers (Bruker Avance III 800, 750 and 600 MHz with cryoprobes). See http://www.scsb.utmb.edu/resources/ UTMB is part of the Texas Medical Center, the world’s largest medical center located in greater Houston. UTMB is situated on Galveston Island offering a pleasant subtropical climate and miles of relaxing beaches. UTMB is located within commuting distance of Houston, the fourth largest city in the United States and a leader in the arts, education, and health care. *Qualifications:* Applicants should have received a Ph.D. degree in a field relevant to structural biology in the past three years and have a strong publication record. Applicants with experience in cloning, bacterial/insect cell culture, protein purification and crystallization, and macromolecular structure determination are preferred. However, recent graduates with a strong background in protein over-expression and purification, and an exceptional interest in learning crystallography are also encouraged to apply. Good written and oral communication skills in English are essential as well as the ability and desire to work as part of a highly motivated, collaborative team. To apply please e-mail the following to *rudenkolab.application(a)gmail.com*<rudenkolab.application(a)gmail.com>: CV, contact information for three references (address, phone and e-mail), a list of your experimental expertise and skills relevant to this position, and a research statement describing your past research experience and future goals (1-2 pages). Visa sponsorship is available for non-US nationals. For questions please contact Dr. Gabrielle Rudenko at <https://web.mail.umich.edu/blue/imp/message.php?mailbox=INBOX&index=111546> *rudenko(a)umich.edu* <rudenkolab.application(a)gmail.com>. For more information please visit http://www.lsi.umich.edu/facultyresearch/labs/rudenko. The University of Texas is a non-discriminatory, affirmative action employer. -- Gabrielle Rudenko PhD Life Sciences Institute and the Dept. of Pharmacology University of Michigan Medical School 210 Washtenaw Ave Rm 3163A Ann Arbor, Michigan 48109-2216 734 - 615 9323 rudenko(a)umich.edu www.lsi.umich.edu/facultyresearch/labs/rudenko

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Re: [phenixbb] Appropriate number of reflections for FreeR
by Edward Berry 03 Nov '13

03 Nov '13

Looking at it from the other side- suppose we say for a robust refinement we need a certain number of reflections- say 4 times the number of atoms, maybe less, I don't know. Any more than that is not really going to affect the structure, So if you have high resolution you can afford to use a large percentage of free reflections, and the cross-validation and maximum liklihood will go really well, even with thin shells. On the other hand at low resolution, well, sorry, you really can't spare any reflections for cross-validation. (I have no idea whether this makes sense or not, but it would be another way of looking at it). >>> Mark van Raaij 11/01/13 7:39 PM >>> the limit of 2000 reflections I guess is just because it would be a waste to "throw away" more reflections for refinement, once the statistical minima for calculating a reliable Rfree have been met. I.e. if you have 100.000 reflections, it would be a waste to use 5 or 10% of the reflections instead of just 2%. I'd rather use as many as possible reflections for refinement. On 31 Oct 2013, at 20:21, Pavel Afonine wrote: > Hi Joe, > > flags should be selected such that there is enough of them in each relatively thin resolution shell (thin enough so ML target parameters can be considered constant in each such shell). Lower end is about 50 reflections per shell. All in all this usually translates into about 10% overall. > > Yes, there is a limit parameter set to 2000 by default. I don't know what's the rationale for having it, may be someone can explain. > > Pavel > > On 10/31/13 12:10 PM, Joseph Noel wrote: >> Hi All. I think I have asked this before but forgot. Old age. What is >> the appropriate number / percentage of reflections to flag for a >> statistically appropriate Free-R calculation? If I am correct, the >> reflection file editor in Phenix chooses by default either 10% of the >> measured reflections or 2000 whichever comes first. >> ______________________________________________________________________________________ >> Joseph P. Noel, Ph.D. >> Arthur and Julie Woodrow Chair >> Investigator, Howard Hughes Medical Institute >> Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics >> The Salk Institute for Biological Studies >> 10010 North Torrey Pines Road >> La Jolla, CA 92037 USA >> >> Phone: (858) 453-4100 extension 1442 >> Cell: (858) 349-4700 >> Fax: (858) 597-0855 >> E-mail: noel(a)salk.edu >> >> Publications & Citations: >> http://scholar.google.com/citations?user=xiL1lscAAAAJ >> >> Homepage Salk: http://www.salk.edu/faculty/noel.html >> Homepage HHMI: http://hhmi.org/research/investigators/noel.html >> ______________________________________________________________________________________ >> >> >> >> _______________________________________________ >> phenixbb mailing list >> phenixbb(a)phenix-online.org >> http://phenix-online.org/mailman/listinfo/phenixbb >> > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://phenix-online.org/mailman/listinfo/phenixbb _______________________________________________ phenixbb mailing list phenixbb(a)phenix-online.org http://phenix-online.org/mailman/listinfo/phenixbb

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Appropriate number of reflections for FreeR
by Joseph Noel 03 Nov '13

03 Nov '13

Hi All. I think I have asked this before but forgot. Old age. What is the appropriate number / percentage of reflections to flag for a statistically appropriate Free-R calculation? If I am correct, the reflection file editor in Phenix chooses by default either 10% of the measured reflections or 2000 whichever comes first. ______________________________________________________________________________________ Joseph P. Noel, Ph.D. Arthur and Julie Woodrow Chair Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: noel(a)salk.edu Publications & Citations: http://scholar.google.com/citations?user=xiL1lscAAAAJ Homepage Salk: http://www.salk.edu/faculty/noel.html Homepage HHMI: http://hhmi.org/research/investigators/noel.html ______________________________________________________________________________________

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Re: [phenixbb] Appropriate number of reflections for FreeR
by Pavel Afonine 03 Nov '13

03 Nov '13

Hi Rongjin, it's not really waste: test reflections are used not only in Rfree calculations, but in ML refinement target parameters estimations, so more test reflections you use better these estimations are, and so better refinement target is. I still believe that 10% is a good number, and any capping the amount of test reflections is NOT necessary: it's not about getting a statistically meaningful amount of them overall, but rather it's about getting the right spread of them across the whole resolution range, and the right amount across all of the thin slices of resolution. I imagine by capping them at a particular number you may end up having a couple of test reflections per certain bin, which isn't great. Pavel On 11/1/13 9:18 PM, Rongjin Guan wrote: > Thank you, Nat and Pavel. I just came back and saw replies from both of > you. Thanks a lot. > I have an impression that free_R set has max 2000 reflections, and more > importantly, each resolution shell has at least > 50 reflections, so I feel >4500 in the free_R set / 150 each shell kind > of luxury ("waste"), and if I have more reflections in the refinement > set, I could have better data/parameters ratio. But this may not make > much difference. > Best, and have a great weekend. > Rongjin > > > On Fri, Nov 1, 2013 at 3:18 PM, Nathaniel Echols <nechols(a)lbl.gov > <mailto:[email protected]>> wrote: > > On Fri, Nov 1, 2013 at 12:13 PM, rjguan <rjguan(a)gmail.com > <mailto:[email protected]>> wrote: > > I solved a structure with 2.7 A Se-Met data set, with 10% > reflections in free_R set. > > Now I have 2.0 A native data set, and extended free_R to 2.0A. > Now I have >4500 reflections > > in free_R set, each resolution shell has >150 reflections. Kind > of too much, right? > > I don't think it's necessarily too much, but it is probably more > than you need. > > > > What is the best way to reduce the number of reflections in the > free_R set, say, to 5%? > > I already built and refined model at 2.7 A, but do not want to > redo autobuild. > > Use the reflection file editor in the GUI - click "More options" in > the section for R-free flags, and check the box "Adjust test set > size to specified fraction". > > > Another question: now I have 2.0A data set, shall I use phases > from 2.7 A data in refinement? > > I compared, without using the phases I got lower R/R_free (about > 1% lower). > > is this because the 2.0 A data is more accurate than the 2.7 A > phases, and I should continue > > to refine at 2.0A without the phases from 2.7 A data? > > It's difficult to reach a conclusion by comparing R-factors alone; > maybe you simply need to run more cycles of refinement with phases > to get the same result. Alternately, if the crystals aren't truly > isomorphous, the phases may be inappropriate for the native > structure. But I think with 2.0Å data and a complete model, it is > perfectly valid to use the amplitudes-only ML refinement target. > > -Nat > >

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Phenix.Rosetta_refine on Ubuntu 12.04 LTS
by Jan Gebauer 31 Oct '13

31 Oct '13

Dear all, I'm trying to get rosetta_refine working on ubuntu 12.04 LTS. This was the (latest) way I tried it: 1) Downloaded phenix-dev-1523 binary & installed it via installer in /usr/local/science/phenix4rosetta/phenix-dev-1523 2) Downloaded rosetta 2031wk42 and extracted it in /usr/local/science/phenix4rosetta/rosetta_2013wk42_bundle 3) Inserted into phenix_env.sh export ROSETTA_BIN=/usr/local/science/phenix4rosetta/rosetta_2013wk42_bundle/main/source/bin export PHENIX_ROSETTA_PATH=/usr/local/science/phenix4rosetta/rosetta_2013wk42_bundle/ export ROSETTA_BIN=/usr/local/science/phenix4rosetta/rosetta_2013wk42_bundle/main/database 4) sources phenix_env.sh 5) build the interface via rosetta.build_phenix_interface nproc=4 6) exceute the refinement via phenix.rosetta_refine phasermodel.pdb data.mtz nproc=4 The programm runs fine, up to the point where it should generate models via rosetta, it then stops and crashes. I have attached some logfiles Has anyone managed to run rosetta_refine on Ubuntu? Which phenix and rosetta versions did you use? Ist there anything wrong on my above mentioned build protocol? I'm thankful for any help. Regards, Jan Gebauer -- Dr. Jan Gebauer AG Prof. Baumann Institut für Biochemie / Uni-Köln Otto-Fischer-Str. 12-14 / 50674 Köln Fon: +49 (221) 470 3212 Fax: +49 (221) 470 5066 http://px.uni-koeln.de/

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warning: do not upgrade Mac OS yet!
by Nathaniel Echols 30 Oct '13

30 Oct '13

There is some kind of strange issue with wxPython on the new Mac OS ("Mavericks"), which for at least the 1.8.4 version prevents Phenix application windows (but not the main GUI) from opening. It is also printing out an extraordinary number of warning messages about fonts to the console. I'm hoping there is a simple solution (which seems likely, since 1.8.2 is mostly okay despite using the same version of wxPython), but until we figure out what is causing this, I recommend leaving your Macs unmolested if you want to use the Phenix GUI. Updates to follow if-and-when I fix this. thanks, Nat

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Using phenix_rosetta_refine
by Jan Gebauer 29 Oct '13

29 Oct '13

Dear all, I tried to install phenix.rosetta_refine for a recently solved structure, which only diffracts up to 3.5-4.0 Angstrom (anisotropic). However, I was unable to get the programs correctly set up. I first tried to compile phenix 1.8.4-1496 from source according to this documentation : http://www.phenix-online.org/version_docs/dev-1500/rosetta_refine.htm. The build process failed during GTK2 building, without an obvious explanation (error code 1, no missing libraries ...) I then realised that the developer version are potentially more suitable, as they seem to be prepared for this. I installed the binary from 1523 and tried to start the building process from there with rosetta.build_phenix_interface nproc=X Unfortunatelly Rosetta 3.5 seems to have a different folder structure. There is no main subfolder, instead there are "rosetta_sources", "rosetta_tools" and so one. After a fast "cp rosetta_sources main/source/" it worked a bit but still exited with: scons: *** Error converting option: extras Invalid value(s) for option: python File ..... /setup.py, line 72, in setup_build_options I have the following questions: 1) Am I right to assume that I do NOT have to recompile the dev 1523 (1520 states "Python shared library for linux) on Linux? 2) Which rosetta version do I have to use? Does 3.5 work? There is no 3.6 on rosettacommons... (or is it hidden?) Regards, Jan -- Dr. Jan Gebauer AG Prof. Baumann Institut für Biochemie / Uni-Köln Otto-Fischer-Str. 12-14 / 50674 Köln Fon: +49 (221) 470 3212 Fax: +49 (221) 470 5066 http://px.uni-koeln.de/

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Need help with atom selection for anisotropic refinement
by Dr. Mark Mayer 28 Oct '13

28 Oct '13

Hi, I'm trying to do a mixed individual isotropic anisotropic refinement b factor refinement and can't get my atom selections to be accepted by phenix.refine. For the atoms I want to do isotropic refinement I used optional (element H or element D or resname HOH or chain E or chain F or chain A or chain B) for the anisotropic selection I used chain A and chain B and not (element H or element D or resname HOH or chain E or chain F or chain A resseq 5:11 or chain A resseq 66:72 or chain A resseq 117:138 or chain A resseq 152:184 or chain A resseq 196:210 or chain A resseq 249:251 or chain B resseq 3:6 or chain B resseq 66:72 or chain B resseq 166:210 or chain B resseq 249:251) I've tried various combuinations, but so far all have given the error message: Selection string results in empty selection. Thanks for your help Mark --

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Alternative Conformation, Restraints
by Moritz Machelett 27 Oct '13

27 Oct '13

Hello everyone, I am in the final rounds of refining my protein at high resolution and currently trying to model an alternative conformation of a Chl /a/-phytol chain. I inserted a second phytol chain with coot - worked out well so far (alternate chain identifiers A and B for both phytol chains). After using phenix.refine, however, the occupancy of the second phytol chain was refined to 0. When splitting the whole Chl molecule the occupancy refines to sensible values (0.34 and 0.66). We would prefer to only model the phytol chain in alternate conformation as the macrocycle superpose perfectly. Any suggestions regarding the occupancy problem? Another issue concerns restraints. We tried to turn of specific nonbonded restraints and found a phenixbb message from 2007: http://www.phenix-online.org/pipermail/phenixbb/2007-September/011734.html Are there any news/updates on this matter? Any help appreciated! Thanks, Moritz -- Moritz M. Machelett Ruhr University Bochum Protein Crystallography, Department of Biophysics, ND04/396 44780 Bochum Tel: +49-(0)234/32-25754

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fem map
by nih\mayerm 27 Oct '13

27 Oct '13

Hi, I'm trying to make a fem amp using phenix-1.8.4-1496 using my refined structure and mtz with map coefficients as input: phenix.development.fem 3222_Glu_refine_78.mtz 3222_Glu_refine_78.pdb coot 0.7.0-1 fails to generate a map when fem.mtz is opened, either in auto or manual mode mtzdmp for fem.mtz gives: Col Sort Min Max Num % Mean Mean Resolution Type Column num order Missing complete abs. Low High label 1 NONE -37 35 0 100.00 -5.0 14.2 61.69 1.21 H H 2 NONE 0 101 0 100.00 38.0 38.0 61.69 1.21 H K 3 NONE 0 44 0 100.00 16.8 16.8 61.69 1.21 H L 4 NONE 0.0 1796.7 25825 84.81 84.67 84.67 31.87 1.21 F 2mFoDFc 5 NONE -180.0 180.0 25825 84.81 1.07 90.28 31.87 1.21 P PHI2mFoDFc 6 NONE 0.0 2750.2 0 100.00 144.76 144.76 61.69 1.21 F 2mFoDFc_FilSharp 7 NONE -180.0 180.0 0 100.00 1.26 90.34 61.69 1.21 P PHI2mFoDFc_FilSharp 8 NONE 0.2 24426.8 0 100.00 235.27 235.27 61.69 1.21 F KICK 9 NONE -180.0 180.0 0 100.00 0.02 89.63 61.69 1.21 P PHIKICK 10 NONE 0.2 9283.0 0 100.00 132.01 132.01 61.69 1.21 F FEM 11 NONE -180.0 180.0 0 100.00 0.23 90.34 61.69 1.21 P PHIFEM

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