October 2020 - phenixbb - phenix-online.org

RapiData 2020 applications open
by Smith, Clyde 16 Nov '21

16 Nov '21

Applications are now open for the 2020 edition of RapiData at SSRL. RapiData is a practical course in macromolecular X-ray diffraction data collection, data processing and structure solution. The aim of the RapiData course is to educate and train young scientists in data collection and processing methods at synchrotron beamlines, using state-of-the-art software and instrumentation. The course will be held in sunny California at the Stanford Synchrotron Radiation Lightsource (SSRL) located on the SLAC National Accelerator Laboratory campus in Menlo Park, CA, from March 30 - April 4 2020. Course organizers for 2020 are Silvia Russi, Clyde Smith and Jeney Wierman. The course will comprise hands-on experiments at the SSRL beamlines, software tutorials, and lectures on the following topics: Specimen preparation, Data collection strategies, X-ray light sources, X-ray detectors, Data reduction, Structure solution by MAD, SAD and Molecular Replacement, Complementary methods (spectroscopy and small angle scattering). Please visit http://smb.slac.stanford.edu/news/rapidata/rapidata-2020/ and use the links on the "registration" page to apply for the course. The application deadline is November 10 2019. Successful applicants will be notified shortly thereafter, and invited to register and book accommodation at the SLAC Guesthouse at that time. A limited amount of travel support funding may be available. Please direct questions to Silvia Russi (srussi(a)slac.stanford.edu), Jeney Wierman (jwierman(a)slac.stanford.edu) or Clyde Smith (csmith(a)slac.stanford.edu).

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Fwd: Re: Number of unique reflections
by Boaz Shaanan 20 Oct '20

20 Oct '20

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Number of unique reflections
by Armando Albert 20 Oct '20

20 Oct '20

Dear all, We have realise that the output mtz and mmcif files duplicate the number of miller indices (the number of unique reflections) with respect to those in the mtz input file. We guessed that this correspond to the friedel pairs, but it is annoying for pdb submission, as the server warns that the observations measured are less that those used in the refinement. What shall we do fro correct this issue? Armando

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What can iNEXT-Discovery do for us?
by a.perrakis＠nki.nl 20 Oct '20

20 Oct '20

Dear all, We are happy to announce a webinar series highlighting some of the experimental possibilities offered by iNEXT-Discovery facilities. iNEXT-Discovery is an H2020 program, that allows scientists from all over Europe (and outside Europe, to some extent) to access state of the art facilities for Structural Biology (X-rays, cryo-EM, NMR, Biophysics). Our offers extend beyond the use of machines, to hands-on expertise and (in many cases) help in designing experiments and interpreting data and of course remote services! Access to iNEXT-Discovery is free (often including samples shipment or visitor expenses) and is on the basis of (rapid) independent peer-review, for projects with a translational research component; the offer extends to industry partners under specific rules. These webinars will be short presentations (20 minutes) presented by experts in the various facilities, and will not be in-depth science talks, but mostly geared towards user awareness for the technical and scientific capabilities we can offer! We will offer one webinar every Monday at 16:00 CET, until Xmas, and then a few more! We will cover topics like cryo-EM single particles and tomography, X-ray tomography, fragment screening by X-ray crystallography, in-cell NMR, and more. Every presentation will be followed by a live discussion. A more detailed program is at: https://inext-discovery.eu/events/what-can-inext-discovery-do-for-us/ Registration is open at: https://zoom.us/webinar/register/WN_ZPGVwe7xR9GIyqESRS-dxA Best regards on behalf of the iNEXT-Discovery team, A. Perrakis Prof. Dr. Anastassis Perrakis, PhD Group leader, Dept. of Biochemistry, Netherlands Cancer Institute Professor of Macromolecular Structures, University of Utrecht Oncode Institute Investigator Coordinator iNEXT-Discovery H2020

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Mask used for map-to-model FSC
by Yang Shi 20 Oct '20

20 Oct '20

Hi all, Does anyone happen to know how to control the tightness of a mask for map-to-model FSC calculation? I have tried the "atom radius" in Map/Model CC tab of "Comprehensive validation (cryo-EM)", but it was not working for me. The reason I am asking this question is that I can only model a small region in the cryoEM map, the rest is unknown to me. Then the CC in low-frequency was 0.4-0.6 in the FSC curve, while the overall masked cc was 0.85. I would like to find an easy way to make the FSC curve look better. Any suggestions would be appreciated! Best wishes, Yang

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Opening Coot through Phenix in Window
by Thomas, Leonard M. 14 Oct '20

14 Oct '20

Hello, Most likely a simple problem, I am helping a some of our students setup their computers to use Phenix and Coot for both their own work and a class. One has installed both Phenix and Coot but cannot get Phenix to open Coot and display the model or maps on a Windows box, Coot is opening just not displaying. I admit I don’t work with Windows that often and I am not sure what the problem could be. Thank you in advance for any insight. Cheers, Len Leonard Thomas, Ph.D. Macromolecular Crystallography Laboratory Oklahoma COBRE in Structural Biology Price Family Foundation Institute of Structural Biology University of Oklahoma Department of Chemistry and Biochemistry Stephenson Life Sciences Research Center 101 Stephenson Parkway Norman, OK 73019-5251 Office: (405)325-1126 lmthomas(a)ou.edu<mailto:[email protected]> http://www.ou.edu/structuralbiology/cobre-core-facilities/mcl

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phenix.resolve_cryo_em resolution and real space refinement
by David Lawson (JIC) 14 Oct '20

14 Oct '20

Hi All, I have run phenix.resolve_cryo_em using half maps at 7.5 A resolution (the postprocessed map is at 7.1 A) and I just wanted to clarify a couple of things (I have pasted the end of the logfile below this message). I set the resolution to 7.52 A but didn't supply a resolution for density modification - it seems to have chosen a value of 5.671 A (1) It states "Estimated improvement of -0.450 A to d_min(FSCref=0.5): 6.628 A" suggesting to me that it agrees with the postprocessed resolution. Is this the value of 7.08 on this line: "FSCref=0.5: 7.08 6.69 6.63"? (2) I understand that the actual process of real space refinement doesn't care about the resolution of the map, but you need to supply it to get meaningful CC values. So my question is what resolution should I supply to RSR if I use the density modified map? I realise that a value of "-0.450 A" is at the upper end of what to expect from density improvement, but I can report that the DM map does look noticeably better than the postprocessed map, especially in regions that are less well defined. Many thanks in advance for any advice Dave Lawson ----------------------------------- d-values (A) where FSCref=0.5: 7.08 6.69 6.63 Estimated improvement in d_cc_star=0.5: -0.450 A This is new current best working_map_coeffs_info. Estimated improvement of -0.450 A to d_min(FSCref=0.5): 6.628 A Done testing....R-value: 0.530 Try: 1 ['database 5', 'resolution: 5.67 ', 'dm_resolution: 5.67 ', 'density_modify_unsharpened_maps:False', 'apply_cc_star:True', 'b_iso: None A**2'] Best density modification cycle 1 is try 1 with Methods used: ['database 5', 'resolution: 5.67 ', 'dm_resolution: 5.67 ', 'density_modify_unsharpened_maps:False', 'apply_cc_star:True', 'b_iso: None A**2'] R-value: 0.530 Estimated improvement of -0.450 A to d_min(FSCref=0.5): 6.628 A Result: -0.450 A to d_min(FSCref=0.5): 6.628 A R-value: 0.530 Wrote working map to /home/lawsond/phenix/ResolveCryoEM_1/map_denmod.ccp4 =============================================================================== SUMMARY AFTER CYCLE OF DENSITY-MODIFICATION =============================================================================== Overall best density modification Cycle 1 try 1 Estimated improvement: -0.450 A to d_min(FSCref=0.5): 6.628 A R-value: 0.530 Denmod resolution: 5.671 A Database: 5.000 A Writing out final map files... ------------------------------- Prof. David M. Lawson Department of Biological Chemistry, John Innes Centre, Norwich, NR4 7UH, UK. Tel: +44-(0)1603-450725 Web: https://www.jic.ac.uk/people/david-lawson Email: david.lawson(a)jic.ac.uk

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Quest for resolution-sensitive substructure determination cases
by Randy Read 11 Oct '20

11 Oct '20

Dear members of the BBs, When determining the anomalous substructure as part of SAD phasing, one of the most important parameters can be the choice of resolution limit for the data provided to the substructure determination algorithm. Extending to too high resolution can hamper the search by introducing too much noise. The resolution limit is varied internally in phenix.hyss, but is provided as a parameter to SHELXD. There are various rules of thumb that people use to make a first choice of resolution limit, such as half-dataset anomalous correlation or the average precision of the anomalous differences, or even just adding 0.5 to dmin. We’re currently exploring some alternative measures and we would like to test them on a significant number of relevant test cases. It turns out that a large proportion of SAD data deposited in the PDB have such good signal-to-noise that substructure determination succeeds with a wide variety of parameters, so we’ve only collected a few cases so far. It would be great if you could let us know of cases that you’re aware of, where substructure determination succeeds with the right choice of resolution limit but fails with the full resolution range of data. Of course, these have to be cases where the diffraction data have been deposited at the PDB or otherwise been made available. We prefer data for which the intensities, and not just the amplitudes, are available, but we won’t be too picky if that would limit the number of examples too much! If you email me directly, I’ll post a summary to the BBs. Thanks! Randy Read ----- Randy J. Read Department of Haematology, University of Cambridge Cambridge Institute for Medical Research Tel: +44 1223 336500 The Keith Peters Building Fax: +44 1223 336827 Hills Road E-mail: rjr27(a)cam.ac.uk Cambridge CB2 0XY, U.K. www-structmed.cimr.cam.ac.uk

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questions regarding phenix.table_one
by Wei Wang 09 Oct '20

09 Oct '20

Dear all, I’m using phenix.table_one to prepare the statistics to include in the paper, and came up with a question regarding the number of reflections being reported. For example, one of the structures has the following statistics: Unique reflections: 70764 (7064) Reflections used in refinement: 70731 (7019) Reflections used for Rfree : 3523 (371) Clearly 70731+3523 is greater than 70764. So I’m puzzled here. I guess “Reflections used in refinement” number actually equals to the sum of "Reflections used for Rfree”+”Reflections used for Rwork”. If this is true then I would just do a simple calculation myself to get the ”Reflections used for Rwork”. Another question is I’m seeing “Reflections used in refinement” always a little smaller than “Unique reflections”. I guess it’s because there’s an outlier rejection in certain step but not sure. I’d be grateful for any clarification. thanks ! Regards, Wei

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phenix.refine read .geo file
by Sheila Boreiko 08 Oct '20

08 Oct '20

Dear all, For the sake of some experiment, I would like to manually edit some restraints of a geometry restraint file (normally named .geo) and ask for phenix.refine to read this edited file rather than producing a new one, is this possible? What should be the command line to read this geometry restraint file be? Thank you, Sheila

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