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protein atom selection
by wtempel 04 Feb '17

04 Feb '17

Hello all, in my hands and to my surprise, PHENIX atom selections such as "protein" or "peptide" would include a co-factor like SAM. Did others notice that also? Is this behavior what most users would want or even expect? Best regards. Wolfram Tempel

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Refine a structure with a disconnected region
by Yasser Almeida Hernández 03 Feb '17

03 Feb '17

Hi all, I am refining a structure at 1.9A, which contains a 7 residues C-terminal region. The resolution of the map in that region is low but is clear enough to define some side chains and the backbone. I build this region manually in Coot. This region is disconnected from the core of the protein, since the connecting loop cannot be seen in the density map. After running phenix.refine (GUI) and playing with the options several times, the final model of this region is always out of the map, even when the R values are improved. How can I refine the structure, keeping that part of the protein in its place, fitted to the map? Thanks in advance Best Yasser

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10th CCP4/APS Crystallographic School in the USA
by Sanishvili, Ruslan 02 Feb '17

02 Feb '17

Dear Colleagues, We are pleased to announce the 10th annual CCP4 crystallographic school “>From data collection to structure refinement and beyond”, held at Advanced Photon Source (APS), Argonne National Laboratory (ANL). All details can be found at http://www.ccp4.ac.uk/schools/APS-2017/index.php Dates: June 19 through 26, 2017 Site: Advanced Photon Source, Argonne National Laboratory, Argonne (Near Chicago), Illinois, USA The school comprises Data collection workshop: beamline training; data collection on GM/CA@APS beamlines 23ID-D and 23ID-B equipped with Pilatus3 6M and Eiger 16M detectors, respectively; and data processing. For data collection, only the participants' crystals will be used. Crystallographic computation workshop: will feature many modern crystallographic software packages taught by authors and other experts. The daily schedule will be organized in three sections – lectures, tutorials, and hands-on, interactive trouble-shooting of the technical difficulties the participants face in their projects. We have had considerable success resolving these problems in past years, attested by resulting publications http://www.ccp4.ac.uk/schools/APS-school/publications.php Applicants: Graduate students, postdoctoral researchers and young scientists at the assistant professor level, along with commercial/industrial researchers are encouraged to apply. Only 20 applicants will be selected for participation. Participants of the workshop are strongly encouraged to bring their own problem data sets or crystals so the problems can be addressed during data collection and/or computation workshops. Application: Application deadline is April 19. The application form, the program, contact info and other details can be found at http://www.ccp4.ac.uk/schools/APS-2017/index.php Registration fees: The registration for application is free but there is $500 participation fee for the selected academic students and $950 for the industrial researchers. The link for the on-line payments and instructions will be provided once the selection process is completed. The students will be responsible for their transportation, lodging and breakfast. The workshop organizers can assist in making the reservations at economical lodging at the Argonne Guest House. The workshop will cover all other expenses. We hope to see you at the school. Garib, Ronan and Nukri Ruslan Sanishvili (Nukri), Ph.D. Macromolecular Crystallographer GM/CA@APS X-ray Science Division, ANL 9700 S. Cass Ave. Lemont, IL 60439 Tel: (630)252-0665 Fax: (630)252-0667 rsanishvili(a)anl.gov

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Announcement: Phenix tutorial videos
by Dorothee Liebschner 01 Feb '17

01 Feb '17

Dear Phenix users, Video tutorials about Phenix tools are now available on the Phenix Tutorial YouTube channel <https://www.youtube.com/channel/UCcdI0hfHngWAZLJWynxPQWg>. The videos give a short introduction about a Phenix tool, summarize the required input files and parameters, explain how to run it and – when appropriate – discuss the results. So far, the following topics are covered: - How to run phenix.refine - How to calculate polder maps - How to run phenix.real_space_refine - How to run PDB tools - How to change phenix.refine parameters via the GUI More videos will be added in the future. Feedback about the videos is very welcome (tutorials(a)phenix-online.org - or use the comment section on YouTube). If you are eager to see a tutorial about a certain (Phenix-related) topic, don't hesitate to tell us: tutorials(a)phenix-online.org. Also, if you want to make your own Phenix tutorial and publish it on the channel, get in touch with us. Further info: To see subtitles, hit the cc (closed captions) button in the right bottom of the video screen. Subscribe to the channel to see the tutorial videos in your YouTube subscription feed. To get notifications about new videos, tap the bell button (next to the "subscribe" button). Best wishes, The Phenix team

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Creating custom peptide bonds
by Pearce, N.M. (Nick) 01 Feb '17

01 Feb '17

Hi, I have a rather odd model situation, where I’m trying to manually create peptide bond restraints between two alternate conformers in refinement. I’m doing this using: ======= ... refinement.pdb_interpretation.apply_cif_link { data_link = TRANS residue_selection_1 = chain "A" and resid " 38 " and altid "B" residue_selection_2 = chain "A" and resid " 39 " and altid "C" } refinement.pdb_interpretation.apply_cif_link { data_link = TRANS residue_selection_1 = chain "A" and resid " 38 " and altid "B" residue_selection_2 = chain "A" and resid " 39 " and altid "D” } ... ======= However, running phenix.refine with this I get the error: ======= RuntimeError: Unused apply_cif_link: TRANS ['pdbres="MET A 38 "', 'pdbres="GLU A 39 “'] ======= Given that the alternate conformers have been removed from the labels, I assume that this can only be used to define links between residues, but not between specific conformers? Is there any way to do this? Thanks, Nick Nicholas Pearce Post-doctoral researcher Universiteit Utrecht

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omit map problems
by Thomas, Leonard M. 01 Feb '17

01 Feb '17

Okay this is a bit frustrating. Trying to run a simple omit map. Have a mtz file used for refinement and the out pdb file from refinement and every time I try to run the script it comes up with No PDB file defined error. Check both files and they appear fine. System is a Mac-Pro running Sierra. Thanks in advance. Leonard M. Thomas Ph.D. Macromolecular Crystallography Laboratory Oklahoma COBRE in Structural Biology Price Family Foundation Institute of Structural Biology Department of Chemistry and Biochemistry University of Oklahoma Stephenson Life Sciences Research Center 101 Stephenson Parkway Norman, OK 73019 405-325-1126 lmthomas(a)ou.edu http://barlywine.chem.ou.edu http://structuralbiology.ou.edu

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Time to submit abstracts for ACA 2017 (May 26-30 in New Orleans)
by Terwilliger, Thomas Charles 31 Jan '17

31 Jan '17

Dear Friends and Colleagues! Mark your calendars and join us in May for the 67th Annual Meeting of the American Crystallographic Association (ACA), to be held May 26-30 in New Orleans, LA, at the Hyatt Regency Hotel. The abstract submission is opened now till February 15th. http://www.amercrystalassn.org/2017-meeting-homepage Back by popular demand - New Orleans ACA Meeting T-shirts with designs on the front and back. Don't be a square and get yours today. Hurry! They can be pre-ordered during the registration or at direct link: https://www.booster.com/aca-meeting-in-new-orleans The meeting will launch with a full day of workshops<http://www.amercrystalassn.org/2071-main-workshops> on four different topics followed by an Opening Ceremony with a plenary lecture by Sir James Fraser Stoddart, 2016 Nobel Laureate in Chemistry. The theme of this year's Transactions Symposium is Cryo Electron Microscopy that will feature lectures by the world's leading researchers and experts. New this year will be a session on NMR crystallography. Both are dedicated to covering topics of importance to scientists with a wide range of professional backgrounds and designed to emphasize our need for collaboration and cooperation. Young researchers<http://www.amercrystalassn.org/2017-young-scientists> will benefit from special and free events such as Career Development, Networking Mixer, Diversity and Inclusion, Communicating Science to Public, Undergraduate Research Symposium as well as educational sessions and workshops. You are encouraged to apply for funding support through travel grants before February 15th, by volunteering, or just contact us if you are many students coming from the same lab. Best regards, Tom T Tom Terwilliger ACA Past President

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question in geometry refinement
by Noelia Bernardo García 27 Jan '17

27 Jan '17

Dear colleagues, I am dealing with the refinement of a protein with 5 monomers in the asymmetric unit at 2.2 Å resolution. Four of them have correct geometry and good density map, however, the fifth molecule has poor density and bad geometry. Ramachandran plot is presents 91.05% (favored), 3.23 % (outliers). I have modified the occupancy of the molecule, the refinement results in 0.8 occupancy for this chain. I also tried to refined the structure without this chain, but the R values increased and the density map indicated that it should be there. I would like to refine this chain fixing the geometry of the others which are correct. Do you have any ideas about how to proceed? Some info: Protein residues 305 5 monomers in the a.u Space group C121 a=151.390, b= 67.81, c=155.420Å, 94.53º R value 0.23 / Rfree 0.28 Many thanks, Noelia Noelia Bernardo García, PhD Instituto de Química Física "Rocasolano" Spanish National Research Council (CSIC) c/ Serrano 119 28006 Madrid (Spain) Phone: +34-91 561 94 00 (ext. 961107) e-mail: xnoelia(a)iqfr.csic.es

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on graphical interface of Phenix 1.10.1-2155-000
by johnpontty＠yahoo.com 26 Jan '17

26 Jan '17

Dear All, For the "refinement settings" in the phenix.refine graphical interface, will you please let me know when we need to change the parameters in "Refinement target weight..."? And is any rule on how to modify the parameters in "Refinement target weight..."? John

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multi-domain protein data, and multi-component/full-featured Phaser-MR
by Emilia C. Arturo (Emily) 23 Jan '17

23 Jan '17

Hello. I have been reading the tutorials and the 2007 McCoy (Acta D) paper about how to use the full-featured Phaser-MR tool (with the Phenix GUI) to do MR. I am struggling with how to define the Ensembles, and the Search procedure. Specifically, after setting up the Ensembles and the Search procedure, as I'd deduced that they should be done, I ran the script and get the following message: >>Search request requires more scattering than defined in composition. Composition increased to accommodate search components.<< I guess that I have not understood how to set up the multi-component search to do what I want for it to do: I'd wanted the tool to search for the best placement of individual domains, given a set of diffraction data and a collection/combination of pdb files that contains coordinates for individual domains. This is the context: The diffraction data is from a crystal of a three-domain protein. The first model I used for MR was a crystal structure of the largest of these domains, which had been expressed and purified alone. With this one domain as a search model (using the single-component Phaser-MR) I obtained a solution without a problem, but now have density into which I will need to place the other two domains. The second-largest domain has also been crystallized (also on its own). Its structure (as a monomer or dimer) is available from different organisms, some dimers engage different inter-chain interfaces, and some have ligands bound at different interfaces. There does exist a crystal structure for the three-domain protein, and its biological assembly is 4. I have reason to think that this new crystal is of this same protein in a different configuration - that is, in this crystal structure the three domains are oriented differently to one another than they were in the first 3-domain structure. In solution this protein can be a dimer or tetramer. The ASU for this dataset is 2 chains, and I assume that each chain has all three domains intact. This diffraction data is of relatively poor resolution (~3.8A). So, I configured the Phaser-MR run as follows, using the AP2 and Beta-blip case studies as examples: - In the 'Ensembles' tab I created 17 different ensembles, each with a different combination of single-domain structures (or with just the single largest domain, as in the original MR single-component search). - In the 'ASU contents' tab I provided the sequence of the full-length (3-domain) protein, and set 'Number of copies' to 2. - In the 'Search strategy' tab I added each of the 17 Ensembles as a separate 'Component' with 'Copies to search for' set to 2. This seems redundant to what I'd put in to the 'Ensembles' tab. I thought that a 'component' meant a single pdb file representing a single chain or domain (in this case) while an 'Ensemble' meant a collection of components so that, e.g., a 3-domain chain could be described as an ensemble of 3 components. Do you have advice on how to set up this search correctly? Regards, Emily. -- "Study as if you were going to live forever; live as if you were going to die tomorrow." - Maria Mitchell "I'm not afraid of storms for I'm learning to sail my ship." - Louisa May Alcott

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