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postdoctoral position at the Institute for Protein Innovation in Boston, USA
by Christopher Bahl 29 Jul '20

29 Jul '20

The Bahl Lab <http://function-structure.org/> at the Institute for Protein Innovation (IPI) in Boston is recruiting Postdoctoral Fellows. We use protein design to accelerate drug discovery and to engineer new lead therapeutic molecules. In addition to traditional academic collaborations, we work closely with pharmaceutical and biotech companies, as well as venture capital firms. We are looking for translationally-minded scientists who want their work to have a direct impact on the world. We will provide training in computational protein design using Rosetta, including de novo protein design and the design of protein function and biophysical properties. Postdoctoral Fellows at IPI leverage our high-throughput automated laboratory infrastructure. We are especially excited to expand our work in the following research areas: - prediction and design of protein developability for therapeutic applications - engineering of de novo miniprotein/peptide lead therapeutics for oncology, infectious disease, hypertension and diabetes, etc. - antibody design, including de novo paratope design - enzyme design Strong candidates will have demonstrated expertise in one or more of the following: - protein biochemistry: protein production and biophysical characterization, enzymology - structural biology: cryo-EM, X-ray crystallography, NMR - immuno-oncology: cell culture models, fluorescence activated cell sorting - traditional protein engineering: directed evolution, library construction, yeast and/or phage display - computational biology: machine learning, data science, molecular dynamics and/or modeling If you are excited to join a team of protein designers working to tackle audacious projects aimed directly at improving human health, please send your CV to: chris.bahl(a)proteininnovation.org About IPI The Institute for Protein Innovation is a non-profit organization that is advancing protein science to accelerate research and improve human health. The Institute is located at Harvard Medical School. IPI uniquely combines the freedom of academic exploration with the high-throughput scaling of industry to take on transformative protein-based initiatives that no other laboratory or organization can or will pursue. IPI is deploying state-of-the-art technologies to build a repository of powerful protein tools and reagents and share them through licensing and collaboration. These will enable new biomedical and therapeutic discovery for researchers in academia and industry alike. This constellation of vanguard technology and expertise positions IPI to train the next generation of entrepreneurs and protein scientists to lead the discovery of new medicines. The IPI is an equal opportunity employer and prohibits discrimination based on ethnicity, religion, sexual orientation, gender identity/expression, national origin/ancestry, age, disability, socioeconomic status, marital or veteran status, etc. Candidates from underrepresented backgrounds are especially encouraged to apply. -- PLEASE NOTE: This message, including any attachments, may include privileged, confidential and/or inside information belonging to IPI. Any distribution or use of this communication by anyone other than the intended recipient(s) is strictly prohibited and may be unlawful. If you are not the intended recipient, please notify the sender by replying to this message and then delete it from your system. Thank you.

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Re: [phenixbb] Phaser-MR output after each component placement
by Randy Read 28 Jul '20

28 Jul '20

Hi Boaz, At the moment, that is indeed the only thing you can do with the partial solution information from the log file. In the CCP4 environment, you can cut and paste lines from the log file to make a .sol file, and use that to run something like a refinement job to produce a PDB and MTZ for a partial solution, but the Phenix environment uses Python pickle files to store the transformations, so that option doesn’t apply. (Unless you run Phaser from a script, in which case the Phenix and CCP4 versions work the same.) At one point, Phaser was writing out a PDB file for the top solution at every point in the process, but we felt that led to clutter and that it was confusing. There’s a major rewrite going on at the moment, and the new phasertng will primarily be run through the phaser.voyager pipeline. One of the design criteria here was to be able to examine branches that weren’t taken or intermediate points in the ongoing search, and to be able to work with them while the overall job is still running. So there will be a better option in the hopefully not too distant future! Best wishes, Randy ----- 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 > On 27 Jul 2020, at 23:02, Boaz Shaanan <bshaanan(a)bgu.ac.il> wrote: > > Hi, > The closest option that comes to mind to do what you're looking for is to take the Euler angles+translations for each of the monomers in the .sol file (or at the top of the final pdb file) and apply each of them to the initial model using any transformation program of your choice. > I am more familiar with running Phaser using the ccp4 gui but it shouldn't be very different under Phenix. > Phaser people may well suggest a more elegant option. > Stay safe, > Boaz > > Boaz Shaanan, Ph.D. > Department of Life Sciences > Ben Gurion University of the Negev > Beer Sheva > Israel > > On Jul 27, 2020 16:02, Johannes Cramer <johannes.cramer(a)gmail.com> wrote: > Dear phenix board, > > does anyone of you know if there is an option in phaser-MR to output a pdb after each placed component? > For example: I suspect there to be 5 molecules in the AU. I start a replacement with 5 molecules and phaser places 1 (I would like to inspect that), 2 (again, I would like to look at the e.g. top 10 results), 3 and so on... > Is that possible? I couldn't find the option in the gui or in the phenix documentation, but maybe in the CLI? > I know I can run one after the other, but that would potentially waste CPU time until I find time to inspect them. > > Cheers, > Johannes > _______________________________________________ > phenixbb mailing list > phenixbb(a)phenix-online.org > http://phenix-online.org/mailman/listinfo/phenixbb > Unsubscribe: phenixbb-leave(a)phenix-online.org

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Visiting Research Specialist Position at the University of Illinois to Study Ribosome Structure
by Yury Polikanov 28 Jul '20

28 Jul '20

The Polikanov Laboratory at the University of Illinois at Chicago (IL, USA) is looking for a talented, skillful, and highly motivated researcher to fill the *Visiting Research Specialist* position to study the structure and function of the bacterial ribosome. The research in the Polikanov Laboratory is focused on understanding the basic principles of protein synthesis in bacteria, the modes of action of ribosome-targeting antibiotics, and the mechanisms of drug resistance at a structural level. More information about Dr. Polikanov's research can be obtained from the most recent publications ( https://www.ncbi.nlm.nih.gov/sites/myncbi/yury.polikanov.1/bibliography/503…) or found on the laboratory web-page ( https://bios.uic.edu/bios/people/faculty/yury-polikanov). The successful candidate will be involved in the determination of high-resolution structures of ribosome functional complexes with various protein translation factors, tRNAs, and antibiotics using macromolecular X-ray crystallography and potentially cryo-EM techniques. *Basic qualifications:* - BS degree in chemistry, biochemistry, biophysics, or a related field; - MS degree or higher is preferred; - Minimum 3 years of laboratory research experience; - Strong background in biochemistry and molecular biology; - Practical skills with the most standard methods currently used in molecular biology, and biochemistry (such as protein expression, purification); - Experience in structural biology (cryo-EM or X-ray crystallography) is desired; - Experience in RNA biology is desired. *The successful candidate is also expected to:* - Act independently in terms of planning and executing the experiments; - Compile, analyze, and prepare data for publications; - Assist with training of graduate and undergraduate students. For fullest consideration, please submit an application and cover letter describing your scientific interests and how your previous research accomplishments and scientific interests fit with the scope of the research in the Polikanov research group at https://jobs.uic.edu/job-board/job-details?jobID=133847 by August 14, 2020. The University of Illinois at Chicago is an Equal Opportunity, Affirmative Action employer. Minorities, women, veterans, and individuals with disabilities are encouraged to apply. The University of Illinois may conduct background checks on all job candidates upon acceptance of a contingent offer. Background checks will be performed in compliance with the Fair Credit Reporting Act.

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Phaser-MR output after each component placement
by Johannes Cramer 27 Jul '20

27 Jul '20

Dear phenix board, does anyone of you know if there is an option in phaser-MR to output a pdb after each placed component? For example: I suspect there to be 5 molecules in the AU. I start a replacement with 5 molecules and phaser places 1 (I would like to inspect that), 2 (again, I would like to look at the e.g. top 10 results), 3 and so on... Is that possible? I couldn't find the option in the gui or in the phenix documentation, but maybe in the CLI? I know I can run one after the other, but that would potentially waste CPU time until I find time to inspect them. Cheers, Johannes

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Adjusting pixel size using phenix
by Noor Agip 23 Jul '20

23 Jul '20

Hi, Is there a way to adjust pixel size of a volume in phenix? I have been using ResolveCryoEM and I would now like to calibrate the pixel of the resulting map. This could be done in chimera but requires resampling the map to a RELION map of the correct pixel size. Best wishes, Noor

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Heme geometry restraint
by Yangqi Gu 21 Jul '20

21 Jul '20

Dear all, I have a question regarding the heme c geometry restraint. I am aware that heme c could undergo distortion when bound to protein, but I am not sure at what resolution I could claim such distortion (such as ruffling/bending/doming). I have a map at 3.6 A resolution and whenever I did the refinement in phenix with real space refinement, some of the hemes are distorted and I am wondering if it is justified to leave it that way or do I have to impose the flat plane geometry. If so, how should I proceed to impose such geometry? Thank you in advance! Best, Yangqi

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mr_rosetta question
by Wei Wang 18 Jul '20

18 Jul '20

Dear all, I would like to get help on a mr_rosetta run. I have a case that 5 copies of searching model was found by Phaser, and I would like to find the sixth one. In addition I would like to improve the building of the MR solution. In such case I’m considering a mr_rosetta run, with some parameters like this: phenix.mr_rosetta seq_file=seq.dat search_models=placed_5_copies.pdb already_placed=true ncs_copies=1 … My question is, should I use the already placed 5 copies model as search_models, with ncs_copies=1, or should I use the original searching model with ncs_copies=6 (in this case I guess I should get rid of the other four copies from the result of Phaser)? For seq.dat, should I use the sequence from one copy of searching model, or paste 5 copies into the seq.dat? Thanks, Wei

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ligand possibly bound to active site cysteine
by Jorge Iulek 18 Jul '20

18 Jul '20

Dear all, I am refining a structure of a Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) (converts glyceraldehyde 3-phosphate into D-glycerate 1,3-bisphosphate) , https://www.brenda-enzymes.org/enzyme.php?ecno=1.2.1.12 . <https://en.wikipedia.org/wiki/Glycerate_1,3-bisphosphate> It turns out that its active center cysteine presents bound ligands , covalently or not to be determined if possible (data resolution 2.51 A). I would like to get help on two issues, (1) what the ligand might be and (2) how to treat it (correct me) in phenix.refine. 1) The protein was expressed in E. coli; it had much contact with glycerol and crystallization conditions include the "ethylene-glycols-mix" ("a mixture of diethylene glycol, triethylene glycol, tetraethylene glycol, and pentaethylene glycol"). Nevertheless, no NAD cofactor was added, and there is no electron density for it. Otherwise, phosphate was also present in crystallization condition. In a previous study, I learned that glycerol might also contain minor amounts of ethylene glycol. I wonder, nevertheless, about glyceraldehyde (and note resemblance with the substrate). Catalytic mechanism includes a hemithioacetal intermediate (https://febs.onlinelibrary.wiley.com/doi/abs/10.1046/j.1432-1327.1998.25204… ) such that cysteine SD is bound covalently to a carbon. I wonder also how much this might attack an ethylene glycol and their likes. Pictures for the density are shown at for the 4 monomers of the a. u., first 4 photos: https://photos.app.goo.gl/Y7MyugqwRFD4sjgDA (blue 1 sig for e. d. maps, green 3 sig for Fourier difference maps) . Density is different among them to different degrees. The nearby threonine, in some cases, seems to interact with a blob (and it is helped by other threonine and a serine) which + - might accommodate a phosphate. I have tried to fit a number of molecules, e.g., the substrate (but not really good in all monomers for the phosphate moiety), glycerol, ethylene glycol and its di and tri (found also in other places in the structure) and now I went for glyceraldehyde (though, I have doubts that there is other - apart from the one eventually bound to S - tertiary carbon). Apart from the difficulties on searching for the best fitting molecule (and consider their intrinsic flexibility) I do not manage to establish distance between them and Cys SD (and there goes the second question). 2) I could not devise how to set a proper distance between any of the ligands and the Cysteine, be it to check for a covalent bond or to establish a van der Waals restriction. I tried: bond { action = *add delete change atom_selection_1 = chain A and resid 153 and name SG atom_selection_2 = chain N and resid 5 and name C3 symmetry_operation = None distance_ideal = 1.803 sigma = 0.1 slack = None limit = -1.0 top_out = False } Results are also show for my Glyceraldehyde trial, last 4 photos, https://photos.google.com/album/AF1QipO71L7GJYKv_MmjTc_0GzsH2xtFR_V-2ICBirPb . Note clashes. Curiously , for some of the bonds to be added, I receive the message: " Atom "HETATM 9835 O2 3GR N 5 .*. O " rejected from bonding due to valence issues." which seems to point to oxygen atoms, though I declare carbon atoms. Helps welcome, thank you. Jorge

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mr_rosetta build test
by Wei Wang 18 Jul '20

18 Jul '20

Dear all, I would like to ask a question about the testing of mr_rosetta build. Is the “phenix_regression.wizards.test_command_line_rosetta_quick" still available? I checked my early build on Mac it is there, but that build was ~3 years ago. However on a recent build on Ubuntu 18.04 the option is not available (I ran the rosetta.run_tests and it’s ok though). Regards, Wei

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occupancy_sum_constraints
by Petros Giastas 16 Jul '20

16 Jul '20

Dear all, I have a metal compound interacting with a protein and I am facing the following problem. Initially, the metal is equatorially complexed with chlorides, which are progressively exchanged by water molecules. This hydrolysis is clear from our spectroscopic analysis, but also from the anomalous maps, which show weaker peaks for the most exposed chlorides. The question regarding phenix.refine is: How can I refine the occupancies of the alternative species (chlorides and water molecules) and to constrain their sum into the occupancy of the metal, which is also under refinement? I cannot find the proper selection syntax to deal with this situation. Can you help me on that? Thank you in advance. Petros P.S. I remember I could treat this kind of problem with shelxl but it has been a lot of time since I last used shelxl for high resolution protein refinement and I would not like to go back.

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