- phenixbb - phenix-online.org

Reference model problem
by Luca Pellegrini 06 Dec '23

06 Dec '23

I am trying to use a reference model in real_space_refinement, but phenix stops with the message: “Cannot not restrain working model to self and a reference model simultaneously” (see below). The reference and working models are identical but bound to different ligands. As far as a I can see, all I am doing is adding the reference model in the input window and ticking the box for reference model restraints (phenix 1.21rc1-4985). Best wishes, Luca Luca Pellegrini, PhD Department of Biochemistry University of Cambridge Cambridge CB2 1GA UK [cid:[email protected]]

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Error 1.21rc1-5156 macOS and cross special position
by Xavier Brazzolotto 01 Dec '23

01 Dec '23

Dear Phenix developers, I have recently updated to macOS Sonoma and updated Phenix to the latest RC (1.21rc1-5156). I do have recent data where a residue gets a bit too close to its symmetric mate. In order to be able to start the refinement, I have to select the model interpretation option « allow_polymer_cross_special_position=True » In this case, the refinement process starts and does my 3 refinement cycles. However, the UI gives me a final error message stating that I have to enable the « cross-special position » (which is already True). The refined data are present (pdb, mtz, log, cif, eff, geo) but I do not get any analysis on these data. No _info.txt, no .kin files. The log ends with a « Sorry » If I deliberately move the faulty residue a bit out of its position (no more clashing with its symmetric mate) and NOT allow the cross-special position, then the refinement ends well with the correct final data analysis. Not a big deal per se, but but I suspect a small issue in the initiation of the analysis programs (Molprobity / King / etc…). Xavier

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Re: [phenixbb] CCP4 Study Weekend 2024 - Early bird registration including standard student bursary deadline coming soon!
by Karen McIntyre - STFC UKRI 01 Dec '23

01 Dec '23

Dear all, Registration is open for the 2024 CCP4 study weekend entitled "Decision making in MX - how to be a productive structural biologist". This year we are focusing on decision-making in macromolecular crystallography: when to use what automated tool, how to interpret the output and when you need to get your hands dirty instead. The frontiers of crystallography now involve massive multi-crystal and multi-dimensional experiments. This means the more that you can leave to the automated pipelines, the more you can focus on the novel elements of your experiment. Sometimes those automated tools work, and sometimes they fail (but have maybe not told you exactly why or how). Sometimes they don't even exist. In that case, how can you return to the basics and develop new strategies to break down the barriers to publication? Once again, this year the CCP4 Study Weekend will be held as a hybrid event from the 3rd to 5th January 2024, enabling people to choose whether to attend in-person or virtually. The in-person event will be held at the East Midlands Conference Centre, Nottingham, UK. We would like to invite you to another iteration of the ever-popular CCP4 Study Weekend - to start the year 2024 with a lot of fresh ideas, new insights and (hopefully) new friends and contacts to boost. As always it will be an eclectic mix of bleeding-edge science, in-depth presentations, discussion panel, poster-sessions, hands-on tutorials and plenty of opportunities for social interactions including the ceilidh. For full details, programme, logistics and registration, please visit the Study Weekend website<https://studyweekend.ccp4.ac.uk/>. Important Key Dates: * Early bird registration final date: 19 November 2023; * Standard Student bursaries are open to all students registering during early bird period i.e. now until 19 November which cover the cost of registration plus one night accommodation; * Registration for in-person delegates closes 4 December 2023 (or earlier if in-person places sell out although you will be able to join the in-person waitlist). We hope to see you there! Scientific Organisers: Helen Ginn (Deutsches Elektronen-Synchrotron, DESY, Germany) Nick Pearce (Linköping University, Sweden) Clemens Vonrhein (Global Phasing Ltd, UK) Administrative Organisers: Karen McIntyre (CCP4, UK)

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The experiment is still very much needed (though AlphaFold helps a lot)
by Tom Terwilliger 01 Dec '23

01 Dec '23

Hi Structural biologist colleagues! Our article that helps you make the case that the experiment is still very much needed is now out: https://www.nature.com/articles/s41592-023-02087-4 "AlphaFold predictions are valuable hypotheses and accelerate but do not replace experimental structure determination." Nature Methods (2023) Also, here is a video on the Phenix Tutorials YouTube channel that describes this analysis: https://www.youtube.com/watch?v=ugMPYdPo8Bc (I hope you will be happy to see that you and your structural biology colleagues get the credit for making AlphaFold possible at 2:35 in the introduction of this video! Keep up the fantastic structural biology work!) All the best, Tom T -- Thomas C Terwilliger Laboratory Fellow, Los Alamos National Laboratory Senior Scientist, New Mexico Consortium 100 Entrada Dr, Los Alamos, NM 87544 Email: tterwilliger(a)newmexicoconsortium.org Tel: 505-431-0010

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Possible problem with eLBOW in version 1.21rc1.5058 using smiles string
by Francisco Javier Medrano 30 Nov '23

30 Nov '23

Dear developers: I have tried to use eLBOW in version 1.21rc1.5058 to generate a cif file for a ligand and the program give me the following error: SMILES parser error:"Unable to load parsing table". The smiles string used was OP(OP(O)(O)=O)(O)=O, but it does not work for other strings. It does work if you supply a pdb file with connect records. If I use version 1.20.1-4487 with the same smiles string it does work properly. Is there any bur in the 1.21 version? Best regards -- Fº Javier Medrano Cristalografía de Macromoléculas Centro de Investigaciones Biológicas Margarita Salas C/ Ramiro de Maeztu, nº 9 Madrid - Spain

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issue with restrains
by Dmitry Semchonok 22 Nov '23

22 Nov '23

Dear colleagues, The issue with the refinement (Phenix 1.21rc1-5130) The refinement does not recognize the phil parameters prepared with ReadySet. [cid:5bb12054-9715-417b-a68d-58c1228ffe56] Please prompt me on how to proceed. Thank you Kins regards, Dmitry

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Errors in atomic coordinates and B factors in MX
by John R Helliwell 20 Nov '23

20 Nov '23

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Question about phenix.resolve_cryo_em
by Reza Khayat 19 Nov '23

19 Nov '23

Hi, Is it possible to turn off the model refinement procedure in phenix.resolve.cryo_em and go straight into density modification? My current model fits reasonably well. Also, Does the routine work well with nucleic acid (e.g. something like RNA from ribosome)? Best wishes, Reza

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EM difference map calculation
by Leonid Sazanov 14 Nov '23

14 Nov '23

Hi, I have tried to use this command in 1.21rc1-4933: phenix.real_space_diff_map XXX.pdb XXX_box.ccp4 resolution=3.0 Model was real-space refined against _box map and the result with map_model_difference_1.ccp4 looks more or less as expected, except that at medium to low density levels strong cubic shape artifacts start to appear. I thought that might be because _box.ccp4 map is not cubic, but re-running with the original cubic map gives even stronger artifacts. Is this a known issue and how this might be resolved? Or perhaps this functionality now comes in one of the newer tools? Many thanks! Leonid -- Prof. Leonid Sazanov FRS IST Austria Am Campus 1 A-3400 Klosterneuburg Austria Phone: +43 2243 9000 3026 E-mail: sazanov(a)ist.ac.at

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Exclude Waters from order_solvent=true updates
by Schulz, Dr. Eike 14 Nov '23

14 Nov '23

Hello everyone, I am refining a few structures via a bash script using constrained occupancy refinement by providing a parameter file. I am trying to model the occupancy of a ligand and the water molecules in its vicinity. This works generally well, but as soon as I switch on ordered_solvent=true, these water molecules are also filtered / updated and eventually removed. How can I avoid this ? That is specifically excluding a number of water molecules from being updated ? With best regards, Eike

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