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Structural Biology Workshop, June 10-12, 2024, Arlington, VA
by Meilleur, Flora 15 Feb '24

15 Feb '24

Dear All, We would like to bring to your attention the 2024 Neutrons in Structural Biology workshop. This workshop will highlight the need for next-generation instruments and toolsets for structural biology, with a focus on neutrons and other complementary techniques, and the development of integrated experimental and computational frameworks that connect them. Neutrons in Structural Biology - Challenges & Opportunities June 10-12th 2024 Sheraton Pentagon City Hotel, Arlington, VA. For details and registration see: Neutrons in Structural Biology - Challenges & Opportunities<https://conference.sns.gov/event/402/> The workshop will include a 1-day satellite training workshop (June 10, 2024) to educate graduate students and postdoctoral researchers in the application of neutron techniques in structural biology. A limited numbers of travel awards are available to support graduate students and post-doctoral fellows attendance at the workshop. The travel award application deadline is April 12, 2024. Details here<https://conference.sns.gov/event/402/page/2891-travel-awards-deadline-april…>. Flora Meilleur on behalf of the organizing committee: Andrey Kovalevsky Flora Meilleur Dean Myles Hugh O'Neill Flora Meilleur, Ph.D. Neutron Scattering Scientist Neutron Sciences Directorate Oak Ridge National Laboratory Professor Molecular & Structural Biochemistry N C State University Editor, Journal of Applied Crystallography Office: 865-576-2779

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to leave atoms out of ADP restraints
by Jorge Iulek 13 Feb '24

13 Feb '24

Hi, all, The ADP restraints I refer to in this discussion are the ones that would make B-factors of nearby atoms to influence (or more or less resemble) each other. For some very disordered side chains, I would like to test "taking out" the "more disordered" atoms (maybe for high chi angle variability) of these restraints, for them to be more free to skyrocket, but also that they do not influence so much the main chain, in some cases where the flexibility difference between main and side chain seems to be significant. Is there a way to do so? Thanks, Jorge

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helical structure - Real space refinement
by Dmitry Semchonok 01 Feb '24

01 Feb '24

Dear colleagues, Is there any specific procedure for Real space refinement in Phenix, having a map and model when working with helical structure? Many thanks Kind regard, Dmitry

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RealSpaceRefine Nucleic acid SS restraints ?
by CUNIASSE Philippe 31 Jan '24

31 Jan '24

Dear all, I am currently refining a protein-nucleic acid structure obtained by MDFF (NAMD) with a 2.9 Å cryo-EM map. Dues to the poor density of the map at the end of the DNA duplex (likely due to breathing at the ends of the duplex), the structure of the DNA tends to be distorted. I tried to set up a set of nucleic acid restraints (Base pairing and base stacking for the full sequence), however, despite the fact that the syntax was checked and no error message is present in the log file, it seems that the restraints are not taken into account as if the constant restraints were two weak. And indeed when examining the refined structure, the pairing and stacking restraints for the base pairs at the extremities of the DNA duplex are not fulfilled. Have you a suggestion to solve this problem ? Thanks in advance for your help. Best regards. Philippe. ----------------------------------------------- Philippe Cuniasse, PhD/HDR. Institute for Integrative Biology of the Cell (I2BC) UMR 9198 CNRS-CEA-Univ Paris Sud Bat 144 CE-Saclay 91191 Gif-sur-Yvette Cedex, France Tel: (33) 1 69 08 56 35 Fax: (33) 1 69 08 47 12 Email: philippe.cuniasse(a)cea.fr<mailto:[email protected]> Web: http://biodev.cea.fr/rasmot3d/ Web: https://www.i2bc.paris-saclay.fr [signature_2602492259]

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leave residue inside its electron density when neighbor is too close
by Murpholino Peligro 29 Jan '24

29 Jan '24

What is the recommended approach to tell phenix.refine to leave the residue inside its electron density? (crystal neighbors) The green model is the input to phenix.refine, the maps and the yellow model are the output of phenix.refine. As you can see, phenix.refine will move the residue outside the density (to avoid clashes I guess?) I have tried setting the occupancy of OXT to 0.5, but it is not good. (you can see there is a water in a special position, just above the bad residue) Any more ideas?

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phenix.mtriage output model-map
by joe.wilson2023 22 Jan '24

22 Jan '24

Dear Phenix team, I am new to Phenix and using the phenix.mtriage to get the map-model FSC results. It gives the correct results at the same time I also want to produce the mode-map used for the FSC calculation. Is there an option for this? If not how can I reproduce the same model-map with another phenix command? Many thanks, Joe

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ResolveCryoEM problem
by Luca Pellegrini 22 Jan '24

22 Jan '24

Hi, I am trying to run Resolve with two half maps and a sequence file with ncs copies of the sequence. Resolve stops with the message: “Need a symmetry file if ncs_copies > 1 and using models”. But I am not using models. Please advise. Regards, Luca Luca Pellegrini, PhD Department of Biochemistry University of Cambridge Cambridge CB2 1GA UK

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Joint X-ray / neutron refinement
by Derek Logan 22 Jan '24

22 Jan '24

Hi phenixbb, I'm trying to understand the current status of joint X-ray/neutron refinement in phenix.refine. The announcement of the latest release mentions a change in the algorithm as described in the recent publication. In the documentation: <https://phenix-online.org/documentation/reference/refinement.html#neutron-a…> Structure refinement in PHENIX<https://phenix-online.org/documentation/reference/refinement.html#neutron-a…> phenix-online.org<https://phenix-online.org/documentation/reference/refinement.html#neutron-a…> [X] <https://phenix-online.org/documentation/reference/refinement.html#neutron-a…> it's described how you can run joint refinement using a parameter file. Does this mean that it is *only* possible in this way and not through the GUI? The GUI was very useful in the past as it automatically opened Coot with the maps for both X-rays and neutrons, and the refinement statistics for both were displayed in the GUI. As far as I can see joint refinement via the GUI last worked in version 1.19.2-4148 from 2021. Best regards Derek

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treating the water molecules in the model
by Dmitry Semchonok 20 Jan '24

20 Jan '24

Dear colleagues, Please share your experience with how you handle the water molecules. So, we have a refined model and added the water molecules using the Douse protocol. So, should we refine the model again afterwards? Or is the model considered ready? We tried to refine our model with water, but then the water molecules flew away from the places. Please let me know what is the correct way to proceed. Many thanks for considering my request. Sincerely, Dmitry

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General interest: Interoperability of crystallographic data and databases
by John R Helliwell 19 Jan '24

19 Jan '24

Dear Colleagues, I imagine you will be interested in this Feature Article on the "Interoperability of crystallographic data and databases" in the current issue of IUCrJ:- https://journals.iucr.org/m/issues/2024/01/00/lt5064/index.html Best wishes, John Emeritus Professor John R Helliwell DSc

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