June 2016 - phenixbb - phenix-online.org

twinning detection
by Ursula Schulze-Gahmen 06 Jun '16

06 Jun '16

I have an extremely low resolution data set to 6.5 A. The data were collected on a Pilatus detector, indexed and further processed in XDS, space group P321. Pointless determines spacegroup to P3221 or P3121 and L-test shows no twinning. Phenix X-triage indicates twinning, but the twin fraction varies enormously depending on the method used: Britton analysis 0.337, H-test 0.260, ML 0.022. The UCLA twin server also thinks that data are twinned. How do I evaluate which information is right? Also, I think I found a molecular replacement solution that is correct using these twinned data. Ursula -- Ursula Schulze-Gahmen, Ph.D. Project Scientist UC Berkeley, QB3 360 Stanley Hall #3220 Berkeley, CA 94720-3220 (510) 643 9491

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GPU acceleration of phenix.real_space_refine?
by Oliver Clarke 02 Jun '16

02 Jun '16

Hi all, phenix.real_space_refine takes a very long time to run on large systems when using any of the more computationally expensive options (e.g. morphing). I was wondering if there has been any consideration towards optimizing this code (and maybe that of phenix.map_to_model) for GPU acceleration? There is somewhat of a shift occuring in the EM community towards using GPU workstations for data processing - if we could use already purchased capabilities to accelerate model refinement as well that would be a huge bonus. I saw a discussion on the bb from a while back concerning the same question applied to phenix.refine, and the conclusion was that in that case the benefits would be minimal, but I'm not sure whether the same applies to real space operations. Cheers, Oli. PS has there been any consideration of including an option to allow users to supply two half maps at run time, one "work" and one "test" map for cross validation purposes? It is possible to do this with two separate runs right now but having the option integrated would be wonderful.

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phenix.real_space_refine GUI
by Pavel Afonine 01 Jun '16

01 Jun '16

Hi Phenix users, since I had to answer this very same question off-list three times in past 48 hours, I thought I post this for future reference... Yes, thanks *Billy* there is a GUI for phenix.real_space_refine (tool to refine atomic models against maps, such as cryo-EM maps)! To give it a try, you need: 1) Get the latest nightly build, dev-2427 for instance: http://phenix-online.org/download/nightly_builds.cgi 2) Enable alpha-test programs in Phenix GUI. To do this: -- start Phenix GUI; -- go to Preferences and tick "Enable alpha-test programs and features" box; -- restart the GUI (close down, then start again); -- phenix.real_space_refine will be available in Refinement section on the right (Real-space refinement [alpha]). Note, it has a very handy feature to see/explore/edit secondary-structure restraints graphically. Also note that *this is alpha-test version meaning that glitches are not unexpected*! However your feedback will help to improve it, so please let us know should you encounter problems, have suggestions or found bug(s)! All the best, Pavel

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r-free flag cell constant mismatch
by wtempel 01 Jun '16

01 Jun '16

Dear Phenix experts, our project involves crystals *A* and *B*, which are nearly isomorphous and of a protein’s complexes with two different small molecules, respectively. *A* diffracts better than *B*. The r-free flag from *A* was “attached” to *B*‘s input reflections with the CCP4 cad command and is still associated to *B*‘s slightly different cell dimensions. Would/should this be reason enough for refine to throw an error? The error message suggests changing the refinement.input.symmetry_safety_check setting. Can this setting be changed in the GUI? Thank you. Wolfram Tempel

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Berkeley Server Downtime (6/3/2016)
by Billy Poon 01 Jun '16

01 Jun '16

Dear all, On Friday, June 3, our servers will be shutdown starting at 6:30 am Pacific for scheduled maintenance in our building (7 - 8 am). This will affect, - The Phenix web site (http://phenix-online.org/) - The DIALS West web site (http://dials.lbl.gov/) - The CCI web site (http://cci.lbl.gov/) - The Structural Biology Technology Portal (http://technology.sbkb.org/) We expect that the servers will be available by 8:30 am Pacific at the latest. Bug reports and emails requesting help should be queued and we will receive them once the servers are back online. We apologize for any inconvenience. -- Billy K. Poon Research Scientist, Molecular Biophysics and Integrated Bioimaging Lawrence Berkeley National Laboratory 1 Cyclotron Road, M/S 33R0345 Berkeley, CA 94720 Tel: (510) 486-5709 Fax: (510) 486-5909 Web: https://phenix-online.org

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Gordon Research Conference on Diffraction Methods
by Edward Snell 01 Jun '16

01 Jun '16

While not a Phenix posting, we do encourage attendance from the usual suspects! We'd like to remind you to register for the Gordon Research Conference on Diffraction Methods to be held at Bates College in Lewiston, Maine, July 17th-22nd 2016. The conference is themed around "Probing the structure and dynamics of macromolecules" and details of the program are at https://www.grc.org/programs.aspx?id=11655. The closing date for applications is June 19th 2016, about 5 weeks away, however GRC conferences have a limited number of participants and we will close registration early if that number is reached. Please join us in Maine this summer for the 40th anniversary of this meeting. If you are planning on attending, please note the deadline, and the growing potential that registration may close earlier. Thanks, Eddie Snell and Arwen Pearson - Chair and co-chair for 2016. Edward Snell Ph.D. CEO Hauptman-Woodward Medical Research Institute Assistant Prof. Department of Structural Biology, University at Buffalo 700 Ellicott Street, Buffalo, NY 14203-1102 Phone: (716) 898 8631 Fax: (716) 898 8660 Skype: eddie.snell Email: esnell(a)hwi.buffalo.edu Heisenberg was probably here!

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