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Cryo_fit
by Reza Khayat 10 Feb '21

10 Feb '21

Hi, The gaussian filter used to prepare cryo-EM maps for cryo_fit is equivalent to a low pass filter. Can anyone suggest a resolution to low pass filter the map to? Or is this value empirically determined by screening through a number of resolutions? Thanks. Best wishes, Reza Reza Khayat, PhD Associate Professor City College of New York Department of Chemistry and Biochemistry New York, NY 10031

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Re: [phenixbb] Cryo_fit
by Kim, Doo Nam 09 Feb '21

09 Feb '21

Hi Reza, Can anyone suggest a resolution to low pass filter the map to? Or is this value empirically determined by screening through a number of resolutions? ==> Yes, this is somehow empirically determined. I think that my predecessors of cryo_fit used to use 15 A, 10 A, 5 A resolution cryo-EM maps successively to avoid being trapped in local minima when they fit ribosome atomic structure into these. Relevant references: https://www.phenix-online.org/documentation/faqs/cryo_fit2_FAQ.html#how-can… cascade mdff in https://elifesciences.org/articles/16105 best, Doo Nam From: <phenixbb-bounces(a)phenix-online.org> on behalf of Reza Khayat <rkhayat(a)ccny.cuny.edu> Date: Tuesday, February 9, 2021 at 11:51 AM To: "phenixbb(a)phenix-online.org" <phenixbb(a)phenix-online.org> Subject: [phenixbb] Cryo_fit Check twice before you click! This email originated from outside PNNL. Hi, The gaussian filter used to prepare cryo-EM maps for cryo_fit is equivalent to a low pass filter. Can anyone suggest a resolution to low pass filter the map to? Or is this value empirically determined by screening through a number of resolutions? Thanks. Best wishes, Reza Reza Khayat, PhD Associate Professor City College of New York Department of Chemistry and Biochemistry New York, NY 10031

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Postdoctoral positions at the Massachusetts Institute of Technology
by Thomas Schwartz 07 Feb '21

07 Feb '21

The Schwartz lab <http://schwartzlab.mit.edu/> at Massachusetts Institute of Technology currently has two open positions for postdocs to work on federally funded projects elucidating structure and function of nucleo-cytoplasmic communication. One project involves the structure of the nuclear pore complex (NPC), in particular with the goal to reduce the resolution gap between crystal structures of NPC components and cryo-ET assembly structures. We work at the interface of bio-engineering and structural biology to solve this problem with innovative methods. The second project centers on the mechanical connections between nucleo- and cytoskeleton via LINC complexes. Here, we want to understand the details for LINC complex engagement, with the lamin layer and with actin filaments, in particular. For both projects, the lab has a vast array of reagents, tools, and expertise to build on. MIT has a brand-new, state-of-the-art, fully-staffed cryo-EM facility <https://nanousers.mit.edu/characterizenano-0/automated-cryogenic-electron-m…> equipped with a Talos Arctica / Falcon 3 and a Titan Krios equipped with a Bioquantum/K3 detector and phase plate. We also have cryo-FIB milling capacity. https://nanousers.mit.edu/characterizenano-0/automated-cryogenic-electron-m… <https://nanousers.mit.edu/characterizenano-0/automated-cryogenic-electron-m…> We seek highly motivated individuals with a passion for structural cell biology. A Ph.D. degree in the life sciences with emphasis on biochemistry/structural biology is desired. Candidates should send their application to Thomas Schwartz at tus(a)mit.edu <mailto:[email protected]?subject=postdoc%20position>.

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Open-rank, tenure-line faculty position
by Hasan, Syed Saif 05 Feb '21

05 Feb '21

Dear Colleagues, The Institute for Bioscience & Biotechnology Research (IBBR) and the University of Maryland, College Park Department of Chemistry & Biochemistry invite applications for an open-rank, tenure-line faculty position in structural biology, with an emphasis in the area of biomolecular cryo-electron microscopy (cryoEM), starting August 2021. The faculty member will base their research program on the IBBR campus in Rockville, Maryland, and hold joint appointments with IBBR and the Department of Chemistry & Biochemistry at College Park. The criteria for selection will be proven excellence and potential for impact through original research, scholarship, and teaching. Successful candidates will be expected to develop a vigorous externally funded research program and have a demonstrated commitment to teaching and mentorship at the undergraduate and graduate levels. IBBR is a joint research institute of the University of Maryland and the National Institute of Standards and Technology (NIST), centrally located in Maryland’s biotechnology corridor. The Institute’s mission is to conduct groundbreaking research in the field of biotechnology that generates innovative solutions to major scientific and engineering challenges. The Institute has a long history of excellence in biomolecular structure-function relationships. Current research programs center on the biomolecular engineering of vaccines, biotherapeutics, and diagnostics; biomolecular measurement science; and disease pathways and biomolecular targets. The available instrumentation at IBBR includes a 200 kV Talos Arctica cryoEM with a Falcon 3EC direct electron detector and a 200 kV Glacios cryoEM with a Gatan K3 direct electron detector and a Volta phase plate. The University of Maryland College Park has a Zeiss EM 10 CA TEM equipped with a tilt stage and a JEOL 100CX II TEM. IBBR instrumentation for sample preparation was recently upgraded with a Thermo Fisher Scientific Vitrobot Mark IV and a Gatan cryoplunge 3. IBBR also maintains a high-performance computing cluster with a dedicated 750 TB parallel file system, and two dedicated 8-GPU nodes. These cryo-EM facilities complement other state-of-the-art instrumentation and expertise at IBBR, including NMR, X-ray crystallography, mass spectrometry, and solution X-ray scattering. For details, please see this advertisement: https://ejobs.umd.edu/postings/80583 Best wishes, Saif S. Saif Hasan, PhD Assistant Professor Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine 108 N. Greene Street, Baltimore MD 21201 https://www.medschool.umaryland.edu/profiles/Hasan-S-Saif-Hasan-Syed-Saif/ Associate Member Program in Oncology, University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center (UMGCCC) 22 S. Greene Street, Baltimore MD 21201 Office and Laboratory Address: Center for Biomolecular Therapeutics, Institute for Bioscience and Biotechnology Research (IBBR) 9600 Gudelsky Drive, Rockville MD 20850 https://www.ibbr.umd.edu/profiles/s-saif-hasan Phone: 240-314-6396 Fax: 240-314-6225

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Postdoc position, Plant Hormone Transporting Membrane Proteins (Denmark)
by Bjørn Panyella Pedersen 05 Feb '21

05 Feb '21

Dear colleagues, I have an open postdoc position funded by the ERC (details below). Please pass this along to anyone who might be interested. Thanks! /Bjørn Postdoctoral position in Structure of Plant Hormone Transporting Membrane Proteins at Aarhus University, Denmark. online posting: https://tinyurl.com/MBGpostdoc We are looking for a highly skilled and motivated postdoc with an interest in working on plant hormone transporting membrane transporters and preferably with a proven track record in the area of structural and/or functional analysis of membrane proteins and an interest for plant biology. Starting date is negotiable. Funding is available through an ERC grant for at least 2 years of employment. An extension is possible for up to a total maximum of 4 years of employment as a postdoc. The position: The position seeks to strengthen ongoing activities in the laboratory of Bjørn P. Pedersen on structure, related to the function and mechanism of plant hormone-transporting membrane proteins as defined by the ERC project MUM-GROW (pedersenlab.dk). Exact project will be shaped out in dialogue with top runners. The laboratory's interest is the interplay between structure and function of transmembrane transport processes with a focus on metabolite uptake systems, and the methods uses are primarily crystallography and cryo-EM. The group is part of the Section of Structural Biology at Aarhus University. The candidate: A successful candidate has a relevant Ph.D. degree and a solid and documented background in structural biology, biochemistry and/or biophysics. Experience with membrane protein expression and purification is favored, and the candidate must demonstrate an ability and interest to work with membrane proteins with a structural aim. Applicants should be ambitious, show strong collaborative skills, and be able to take initiatives and responsibility within the work environment. The successful candidate is offered: - access to a well-developed research infrastructure. - a research climate inviting lively, open and critical discussion within and across different fields of research. - a working environment with teamwork, close working relations, network activities among young scientists and social activities. - a workplace characterized by professionalism, equality and a healthy work-life balance. The city: In Aarhus you have easy access to beautiful nature, an exciting culture and city life as well as a safe environment for children - a great place for the whole family. The city of Aarhus has everything you need: exciting national and international jobs, delightful residential areas, a rich cultural life, and beautiful surrounding landscape of woods and coastline that make Aarhus a wonderful place to live and work. See https://international.au.dk/life/ for details. Aarhus University offers relocation service to international researchers. You can read more about it at https://international.au.dk/life/researcherscomingtoau/. Deadline: All applications must be made online (https://tinyurl.com/MBGpostdoc) and received by March 1st 2021.

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Re: [phenixbb] refinement with translational ncs
by Jorge Iulek 31 Jan '21

31 Jan '21

Dear Esko, Thank you for your input. I must also look into these papers. Jorge On 1/27/21 10:02 AM, Esko Oksanen wrote: > Dear Jorge, > > With significant translational pseudosymmetry, at least close to a > pseudo-centerering vector, will inevitably lead to higher R-values. > Basically the R-value isn’t a very good indicator of the structure > correctness any more and the expected values for an acentric structure > are no longer really valid. I had a somewhat similar case long ago > (https://doi.org/10.1107/S0907444906031519) and since then there is a > nice paper summarising the effects of pseudosymmetry > (https://doi.org/10.1107/S090744490705531X). > > HTH, > Esko > *_____________________* > * > * > *Esko Oksanen, PhD* > Instrument Scientist - Neutron Macromolecular Crystallography > > European Spallation Source ERIC > P.O Box 176, SE-221 00 Lund, Sweden > Visiting address: Odarslövsvägen 113 224 84 Lund Sweden > Switchboard: +46 46 888 00 00 > Phone: +46 721 79 20 36 > E-mail: esko.oksanen(a)ess.eu <mailto:[email protected]> > > www.ess.eu <http://www.esss.se/> > > > > > > > > >> On 27 Jan 2021, at 11:46, Jorge Iulek <iulek(a)uepg.br >> <mailto:[email protected]>> wrote: >> >> Dear all, >> >> >> I have a dataset at 2.98 A resolution, images processed to CC_1/2 >> at circa 50% in the last resolution shell, tetramer in the asymmetric >> unit, local (rotational) symmetry 222. Xtriage indicates a peak in >> the Patterson function at 20% height of origin peak, at fractional >> coordinates of 0.0000 0.0000 0.3177. Space group is P21. >> >> I am aware that this brings problems to refinement , as even >> stated at xtriage output "Translational pseudo-symmetry is very >> likely present in these data. Be aware that this will change the >> intensity statistics and may impact subsequent analyses, and in >> practice may lead to higher R-factors in refinement.", and so I can't >> lower my R and R-free below ~31 and 36 % , respectively. >> >> At phenix.refine, setting "tncs_correction = True" brings little >> benefit (what does this actually do? points to references are >> welcome). I wonder nevertheless if some strategy might help in on >> lowering these R's and, of course, allow me to build a better model >> (in spite of the resolution). I tried some combinations of other >> types of ncs and tls groups, with little success. Particularly, it >> seems that the refinement of ADPs are a kind of unstable (what I >> would understand come from the - partial - modular nature of the >> intensities - due to tncs - and these - ADP - would be reflected by >> the intensity fall-off with resolution). What about refining ADPs >> only to a zone which is not affect by data modulation? How to do >> that? Any other ideas? >> >> Thanks, >> >> >> Jorge >> >> >> >> >> _______________________________________________ >> phenixbb mailing list >> phenixbb(a)phenix-online.org <mailto:[email protected]> >> http://phenix-online.org/mailman/listinfo/phenixbb >> Unsubscribe: phenixbb-leave(a)phenix-online.org >

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refinement with translational ncs
by Jorge Iulek 31 Jan '21

31 Jan '21

Dear all, I have a dataset at 2.98 A resolution, images processed to CC_1/2 at circa 50% in the last resolution shell, tetramer in the asymmetric unit, local (rotational) symmetry 222. Xtriage indicates a peak in the Patterson function at 20% height of origin peak, at fractional coordinates of 0.0000 0.0000 0.3177. Space group is P21. I am aware that this brings problems to refinement , as even stated at xtriage output "Translational pseudo-symmetry is very likely present in these data. Be aware that this will change the intensity statistics and may impact subsequent analyses, and in practice may lead to higher R-factors in refinement.", and so I can't lower my R and R-free below ~31 and 36 % , respectively. At phenix.refine, setting "tncs_correction = True" brings little benefit (what does this actually do? points to references are welcome). I wonder nevertheless if some strategy might help in on lowering these R's and, of course, allow me to build a better model (in spite of the resolution). I tried some combinations of other types of ncs and tls groups, with little success. Particularly, it seems that the refinement of ADPs are a kind of unstable (what I would understand come from the - partial - modular nature of the intensities - due to tncs - and these - ADP - would be reflected by the intensity fall-off with resolution). What about refining ADPs only to a zone which is not affect by data modulation? How to do that? Any other ideas? Thanks, Jorge

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Postdoctoral Fellow Position in CFTR biology at AbbVie
by Jain, Rinku 26 Jan '21

26 Jan '21

Hello Everyone, A postdoctoral position is available immediately in the Cystic Fibrosis Group led by Dr. Ashvani Singh at AbbVie Inc, in Illinois, USA. Successful candidate will work with a cross-functional team of researchers to Investigate the Structure-Function Relationship of CFTR Using CFTR Modulators and Understand their Clinical Translation. Qualified candidate should have a PhD in Biochemistry (Biochemistry/Pharmacology/Cell and Molecular Sciences/Structural Biology) with no more than 3 years of prior postdoctoral experience. Experience in membrane protein expression, purification and biochemistry is required and a strong background in CFTR pharmacology is preferred. Key responsibilities include expression and purification of disease mutants and biochemical, biophysical, and structural studies. Previous experience in Cryo-EM is preferred but not essential. Selected candidate will have the opportunity to learn Cryo-EM. For more information and to apply online, please visit: https://careers.abbvie.com/jobs/2007216?lang=en-us#.X48n8qJQthg.mailto Req ID: 2100410 Thanks, Rinku

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Phenix version 1.19.1 released
by Paul Adams 25 Jan '21

25 Jan '21

The Phenix developers are pleased to announce that version 1.19.1 of Phenix is now available (build 1.19.1-4122). This fixes bugs in the 1.19 release. If you have previously downloaded 1.19 we recommend upgrading to 1.19.1. Binary installers for Linux, Mac OSX, and Windows platforms, and the source installer, are available at the download site: http://phenix-online.org/download/ Highlights for the 1.19.1 version of Phenix: - phenix.real_space_refine - Fix bug in restoring previous jobs - Clarify NCS options Please note that this new publication should be used to cite the use of Phenix: Macromolecular structure determination using X-rays, neutrons and electrons: recent developments in Phenix. Liebschner D, Afonine PV, Baker ML, Bunkóczi G, Chen VB, Croll TI, Hintze B, Hung LW, Jain S, McCoy AJ, Moriarty NW, Oeffner RD, Poon BK, Prisant MG, Read RJ, Richardson JS, Richardson DC, Sammito MD, Sobolev OV, Stockwell DH, Terwilliger TC, Urzhumtsev AG, Videau LL, Williams CJ, Adams PD: Acta Cryst. (2019). D75, 861-877. https://doi.org/10.1107/S2059798319011471 Full documentation is available here: http://www.phenix-online.org/documentation/ There is a Phenix bulletin board: http://www.phenix-online.org/mailman/listinfo/phenixbb/ Please consult the installer README file or online documentation for installation instructions. Direct questions and problem reports to the bulletin board or: help(a)phenix-online.org and bugs(a)phenix-online.org Commercial users interested in obtaining access to Phenix should visit the Phenix website for information about the Phenix Industrial Consortium. The development of Phenix is principally funded by the National Institute of General Medical Sciences (NIH) under grant P01-GM063210. We also acknowledge the generous support of the members of the Phenix Industrial Consortium. -- Paul Adams Division Director, Molecular Biophysics & Integrated Bioimaging, LBL (http://biosciences.lbl.gov/divisions/mbib) Principal Investigator, Computational Crystallography Initiative, LBL (http://cci.lbl.gov) Vice President for Technology, the Joint BioEnergy Institute (http://www.jbei.org) Principal Investigator, ALS-ENABLE, Advanced Light Source (http://als-enable.lbl.gov) Division Deputy for Biosciences, Advanced Light Source (https://als.lbl.gov) Laboratory Research Manager, ENIGMA Science Focus Area (http://enigma.lbl.gov) Adjunct Professor, Department of Bioengineering, U.C. Berkeley (http://bioeng.berkeley.edu) Adjunct Professor, Comparative Biochemistry, U.C. Berkeley (http://compbiochem.berkeley.edu) Building 33, Room 250 Building 978, Room 4126 Building 977, Room 180C Tel: 1-510-486-4225 http://cci.lbl.gov/paul Lawrence Berkeley Laboratory 1 Cyclotron Road BLDG 33R0345 Berkeley, CA 94720, USA. Executive Assistant: Ashley Dawn [ ashleydawn(a)lbl.gov ][ 1-510-486-5455 ] --

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real space rotamer restrains
by Leonid Sazanov 22 Jan '21

22 Jan '21

Hi, Is there somewhere a description of all the new parameters in phenix.real_space_refine rotamer restrains? I mean rotamers { fit = all *outliers_or_poormap outliers_and_poormap outliers poormap restraints { enabled = True sigma = Auto target = max_distant min_distant exact_match fix_outliers } tuneup = outliers outliers_and_poormap } What is poormap? What is the range of Sigma? What are those types of target? With the latest nightly build, with default parameters starting model with 1% of rotamer outliers ends up with 10% (not using local_search, as it was done before). To minimise number of outliers, which parameters can be changed? Lower Sigma? Switch on tuneup? Thanks for any info! 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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