May 2016 - phenixbb - phenix-online.org

Postdoc positions at Arizona State Uni: algorithm development for XFEL data
by Nadia Zatsepin 20 May '16

20 May '16

*Open positions: 2 Postdoc positions in XFEL Biophysics at Arizona State University.* Full details & how to apply: *https://physics.asu.edu/about/employment-opportunities <https://physics.asu.edu/about/employment-opportunities>* We are applicants for 2 postdoctoral researcher positions for the development of algorithms for biological X-ray free electron laser (XFEL) data, both in crystallography and solution scattering. The successful applicants will become part of an interdisciplinary team at ASU working on solving important biological questions using XFELs. This is a two-year Postdoctoral appointment with the possibility of extension to a maximum of three years. *Objectives* The objective of these postdoctoral researcher positions is to develop algorithms for improving data accuracy in SFX through modeling and optimization, develop novel phasing methods which exploit the full spatial coherence of the XFEL for 2D and 3D nanocrystals, and/or develop structure-determination methods that can be applied to samples that cannot be crystallized, through XFEL fast solution scattering. *Essential Functions of the position:* - Develop improved algorithms and software for analyzing biological XFEL data (static and time-resolved crystallographic or solution scattering data). - Analyze and present results at conferences, workshops, seminars and technical meetings. - Document and publish research results in peer-reviewed scientific or technical journals. - Contribute to XFEL data analysis workshops organized by the Group The successful candidates are expected to support the analysis of serial femtosecond crystallography experiments at the Linac Coherent Light Source (LCLS), SPring-8 Angstrom Compact free electron Laser (SACLA), the European X-Ray Laser (XFEL), or other applicable x-ray sources (XFELs or 3rd generation synchrotrons). This work is complementary to XFEL data analysis work in the NSF BioXFEL Science and Technology center (STC), and so the candidates will interact and collaborate with students and postdoctoral researchers working in the BioXFEL STC. They will report to the PI for the project. *Required Qualifications:* - PhD in related field such as physics, biophysics, bioinformatics, structural biology, by time of appointment. - Experience in analysis of X-ray diffraction imaging or crystallographic data. - Demonstrated algorithm and/or code development. - Demonstrated publication record in peer-reviewed literature; and experience in presenting research results to large audiences. - Demonstrated ability to perform independent research and in a diverse team environment to achieve program goals in a timely fashion. - Demonstrated fundamental verbal and written communication skills (in English) necessary to work in a multidisciplinary team environment, author technical and scientific reports and publications, and deliver scientific presentations. *Desired Qualifications:* - Experience with X-ray experiments at synchrotrons or XFELs related to high-resolution imaging or crystallography. - Experience and familiarity with coherent x-ray imaging experiments. - Experience with analyzing and solving protein structures. - Demonstrated programming experience in C and Python; experience with , web-interface development - Experience with parallel programming and large data sets. *To apply, *please submit as a single PDF document: (1) a cover letter which includes the names and email addresses of three references, (2) a curriculum vitae with a list of publications. PDF application materials should be submitted via the employment application portal. <https://physics.asu.edu/content/postdoc-position-job-11577-0> *Applications will be reviewed beginning June 15, 2016.* If not filled, every week thereafter until the search is closed. *Anticipated starting date: August 2016. * Please email nadia.zatsepin(a)asu.edu for more information. -- Nadia Zatsepin Assistant Research Professor Dept of Physics PSF246 Arizona State University +1 480 727 6444 nadia.zatsepin(a)asu.edu *http://www.public.asu.edu/~nzatsepi/ <http://www.public.asu.edu/~nzatsepi/>*

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Rfree doesn't decrease and keeps around 36%, High ramachandran outlier, High RMSD
by chen c 14 May '16

14 May '16

Dear all, I am solving a structure which diffracted to 2.8 angstrom resolution and containes 8 molecules (MW:12 kDa) per ASU. It's noteworthy that though the model used for molecular replacement shares 50% sequence identity with my protein, however, severe clashes were found as listed below: Packing Table ------------- Solutions accepted if total number of clashes <= 5% of trace atoms i.e. total number of clashes <= 32 AND if number of clashes <= 5% of trace atoms for each ensemble i.e. ensemble1: number of clashes <= 4 # # #Clash Packs SpaceGroup Annotation 1 17 NO C 2 2 21 ... PAK=11 LLG=802 RFZ=3.8 TFZ=9.3 Only after I changed the packing criteria from 5% to 100%, can I get the solution. Severe clashes and even coincidence of different molecules were found as briefly listed below: Molecule A (C-terminal) vs Molecule D (N-terminal) of neighbouring ASU Molecule B (C-terminal) vs Molecule C (N-terminal) Molecule C (C-terminal) vs Molecule D (C-terminal) Molecule E (C-terminal) vs Molecule G (N-terminal) Molecule F (C-terminal) vs Molecule H (N-terminal) Molecule G (C-terminal) vs Molecule G (C-terminal) of neighbouring ASU Molecule H (C-terminal) vs Molecule H (C-terminal) of neighbouring ASU Upon this, I manually rebuild the structure in COOT and particularly deleted those coincided atoms. Then I refined the structure in phenix. However, all the refine gives a bad result, namely, RMSD(angle) at 1.8-2.1, RMSD(bond) at 0.015-0.02, The Rwork/Rfree at around 0.28/0.36, Ramachandran outlier + Rotamer outlier at around 15-20%. I tried a lot of refinement strategy and the current status is : RMSD(angle)= 1.545, RMSD(bond) = 0.01, Rwork/Rfree = 0.290.36, Ramachandran outlier=11.3%,Rotamer outlier =1.5%. The data set belonged to C2221 and phenix.xtriage analysis reflects no twinning or pseudotranslation problem. In addition, there are two beta-turns in each molecule which displays poor electron density and geometry. And this two loop are the very residues which appears in disallowed regions in ramachandran diagram apart some other residues. However, these residues should have little effect on the R factor considering of their low contribution to the overall structure due to their poor electron density. Has anyone has experiences about this? Your help and advice is greatly appreciated! Thank you! Chen -- Cheng Chen, Ph.D. Candidate Laboratory of Structural Biology Life Science Building,Tsinghua University Beijing 100084 China Tel:+86-10-62772291 Fax:+86-10-62773145 E-mail:[email protected] 北京市海淀区清华大学生命科学馆201-212室邮编：100084

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occupancy refinement with constrained groups
by Schnicker, Nicholas J 14 May '16

14 May '16

Dear all, I am trying to do use constrained groups with occupancy refinement but struggling with syntax. I am trying to define selection1 as 2 different atoms and selection2 as another 2 different atoms. Therefore I want the 2 atoms in selection1 to have the same occupancy and the atoms in selection2 to have the same and the sum of selection 1 and 2 will be 1. If someone could help me with this syntax I would appreciate it! I have tried using brackets to separate selections but phenix doesn't recognize this. I can provide more information if needed, it's just a complicated scenario. Thanks! Nick

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FreeR flags from AutoBuild
by Sam Tang 14 May '16

14 May '16

Dear all May I enquire a simple question about AutoBuild - I input an experimental data (ccp4 mtz from Aimless) and a model from Phaser-MR to AutoBuild hoping that some mis-fit flexible regions could be re-build. May I know if the output mtz *overall_best_refine_data.mtz* contains the same FreeR flags as in the input, or would AutoBuild generate a new set of FreeR? Or in other words, are the R values directly comparable if I refine against the input experimental data mtz or the overall_best_refine_data.mtz? Thanks! Cheers Sam Tang Biochemistry Programme, School of Life Sciences, CUHK

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FW: [SA_Scat] 4th Annual CCP-SAS Project Meeting
by Kushol Gupta 13 May '16

13 May '16

---------- Forwarded message ---------- From: <stephen.king(a)stfc.ac.uk> Date: Mon, May 9, 2016 at 5:27 AM Subject: [SA_Scat] 4th Annual CCP-SAS Project Meeting To: sa_scat(a)iucr.org Dear Colleagues, We are pleased announce the 4th Annual CCP-SAS Project Meeting to be held at the NIST NCNR, Gaithersburg MD, USA from Mon 23 through Wed 25 May 2016. CCP-SAS includes the SASSIE and SCT suites of 'atomistic' modelling software. The Meeting program is available online at http://www.ccpsas.org/Meetings/Fourth/Program.html This year the Meeting also includes two 'hands-on' Tutorial Sessions on Wed 25 May: one aimed at those who wish to learn how to incorporate additional modules into the SASSIE Framework, and another aimed at those who wish to learn about wrapping applications for Web deployment using GenApp. Registration for the Meeting and Tutorials is FREE, but space is limited and places will be allocated on a first-come, first-served basis. IMPORTANT: As the meeting is being held on the NIST Campus, registration with NIST is mandatory. Please follow the 'Registration' link on the above webpage. Photo ID will be required for entry. There is also the opportunity to present relevant posters on Mon 23 May. Please contact Prof Paul Butler (pbutler(a)utk.edu<mailto:[email protected]>) if you would like to do this. On Tue 24 May there will be a special Workshop for potential future collaborators, software developers, and funders. Attendance at this Workshop is by invitation only. Please also contact Paul Butler (pbutler(a)utk.edu<mailto:[email protected]>) if you might like to contribute to these discussions. We hope you can join us! The CCP-SAS Team

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bug?
by Patrick Loll 13 May '16

13 May '16

I just ran into something that might be a small bug (phenix 1.10.1-2155) Background: I have a problem data set for which the unit cell is too small to hold we thought we were crystallizing (which probably means we crystallized the wrong protein). In any case, I ran the data through Xtriage, supplying the sequence file for the too-large protein, even though I knew this is probably not correct. This sequence file contains 264 residues. I was surprised to see that the program returned with a perfectly reasonable estimate of the Matthews coefficient, making me briefly hopeful that I had been doing the calculation incorrectly. Alas, not so; when I dig through the log file, I find the following: ____begin excerpt_______________________________________________________________ determining composition from sequence file /xxxx/seq.dat Too many residues to fit in the ASU resetting numer of residues in monomer to 26 =================== Solvent content and Matthews coefficient ================== Crystallized molecule(s) defined as 264 protein residues ------------------------------------------------------------------- | Solvent content analysis | |-----------------------------------------------------------------| | Copies | Solvent content | Matthews coeff. | P(solvent content) | |-----------------------------------------------------------------| | 1 | 0.666 | 3.68 | 0.621 | | 2 | 0.331 | 1.84 | 0.379 | ------------------------------------------------------------------- Best guess : 1 copy in the ASU _____end excerpt_______________________________________________________________ So it seems as though the program, when confronted with a protein mass that’s too large for the AU, divides the mass by 10 and tries again. However, this is not clear from the results; in the results section, it states “Crystallized molecule(s) defined as 264 protein residues." So a user might be misled into thinking that everything is OK, when in fact it’s not… Cheers, Pat --------------------------------------------------------------------------------------- Patrick J. Loll, Ph. D. Professor of Biochemistry & Molecular Biology Director, Biochemistry Graduate Program Drexel University College of Medicine Room 10-102 New College Building 245 N. 15th St., Mailstop 497 Philadelphia, PA 19102-1192 USA (215) 762-7706 pat.loll(a)drexelmed.edu

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BCA/CCP4 Summer School 2016 - Applications now open
by Airlie McCoy 10 May '16

10 May '16

I am pleased to announce that applications are now open for the BCA/CCP4 Summer School in Protein Crystallography to be held at Diamond Light Source from Sunday 21st August to Friday 26th August 2016 Applications will close Friday 13th May. The registration fee of the school has been kept low due to the generous sponsorship of the BCA and CCP4. Note that up to 10 free places are available to BBSRC funded students. For a draft programme and application details see: http://www.diamond.ac.uk/Home/Events/2016/BCA-Summer-School.html The BCA/CCP4 Protein Crystallography Summer School is intended for students and researchers new to crystallography. Its dual aims are to provide comprehensive training in crystallography and to promote best practise within the British crystallographic community. The lectures cover the gamut of techniques required for a structure solution, from protein expression through to structure validation. Intensively supervised computer tutorials enable students to relate the theory presented in the lectures to practice. Although CCP5 programmes will primarily be used in these tutorials, the aim will be to approach crystallographic questions in a software-agnostic manner. There will also be a crystal manipulation and cooling workshop. (Note that the course is scheduled during Diamond synchrotron downtime, so there will not be active data collection at the Diamond beamlines.) We recognise that an active social programme plays a role in enabling students to make links that may be maintained throughout a research career. There will be a conference dinner, and a number of other events, including a boat trip on the Thames from Oxford. Airlie McCoy

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Research Technician Position at Structural Biology Lab at University of Southern California
by Xiao Lei 08 May '16

08 May '16

Dear All, The Lin Chen laboratory at the University of Southern California is seeking a research technician to join the lab. The Chen lab is interested in the structure and function of molecular complexes that control cell signaling and gene expression. We use a multi-disciplinary approach that combines structural biology, chemical biology, biochemistry/cell biology, and computational biology/bioinformatics to study the molecular basis of signal transduction and transcription regulation. For more detailed description of our research, please visit the lab page: http://structure.usc.edu/ Job Responsibilities Include: Assist postdoctoral fellows and graduate students in the lab on a variety of biochemical and biophysical studies, including gene cloning, protein expression, purification, and characterization of purified protein by various biochemical and biophysical techniques, and protein crystallization. The technician may also be involved in developing new techniques to study the structure and function of the genome. The technician is also expected to take a small amount of lab managing duty such as ordering and organizing lab supplies,. Commitment of 1 year is required; 2 years is preferred, the position is grant-funded and renewable Preferred Qualifications: • BS in Biochemistry, or Chemistry, or Molecular Biology, or related field • 2 years lab experience • Working knowledge of laboratory equipment and research protocols • Must be meticulous, detail-oriented, and responsible • Basic biochemistry, molecular biology and chemistry knowledge To apply for this position, Please send CV, three names of reference and a cover letter to: linchen(a)usc.edu Best Regards.

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autoBuild error, OSError: [Errno 12] Cannot allocate memory
by luzuok 07 May '16

07 May '16

Hello, The autobuild had been running for almost 2 hours in my Desktop, but it suddenly stopped and posed an error message as indicated below. Is this caused by my insufficient memory? Best wishes! Luzuokun Splitting work into 4 jobs and running with 2 processors using sh background=True in /home/lu/Documents/StructurePro/why/P43212/AutoBuild_run_2_/TEMP0 Starting job 1...Log will be: /home/lu/Documents/StructurePro/why/P43212/AutoBuild_run_2_/TEMP0/RUN_FILE_4.log Starting job 2...Log will be: /home/lu/Documents/StructurePro/why/P43212/AutoBuild_run_2_/TEMP0/RUN_FILE_5.log Starting job 3...Log will be: /home/lu/Documents/StructurePro/why/P43212/AutoBuild_run_2_/TEMP0/RUN_FILE_6.log Starting job 4...Log will be: /home/lu/Documents/StructurePro/why/P43212/AutoBuild_run_2_/TEMP0/RUN_FILE_7.log Traceback (most recent call last): File "/usr/local/phenix-1.10.1-2155/modules/phenix/phenix/autosol/AutoBaseExtend.py", line 987, in DoNextMethod self.CarryOutBest() # to be obtained after it is finished File "/usr/local/phenix-1.10.1-2155/modules/phenix/phenix/autosol/AutoBaseExtend.py", line 2147, in CarryOutBest getattr(self,str(self.application_method))() # call this fn File "/usr/local/phenix-1.10.1-2155/modules/phenix/phenix/wizards/AutoBuild.py", line 2372, in AutoBuild_build_cycle self.AutoBuild_rebuild_cycle_run() File "/usr/local/phenix-1.10.1-2155/modules/phenix/phenix/wizards/AutoBuild.py", line 4714, in AutoBuild_rebuild_cycle_run always_reuse_model=always_reuse_model) File "/usr/local/phenix-1.10.1-2155/modules/phenix/phenix/wizards/AutoBuild.py", line 7589, in AutoBuild_build_refine mtz_file=mtz_file,mtz_ref_file=mtz_ref_file) File "/usr/local/phenix-1.10.1-2155/modules/phenix/phenix/wizards/AutoBuild.py", line 7833, in run_standard_build_in_parallel r.run(out=sys.stdout) File "/usr/local/phenix-1.10.1-2155/modules/phenix/phenix/autosol/run_group_of_wizards.py", line 294, in run self.start_run(run_file,last=is_last) File "/usr/local/phenix-1.10.1-2155/modules/phenix/phenix/autosol/run_group_of_wizards.py", line 604, in start_run cmd+" "+self.add_double_quote(run_file,escape_space=False)) File "/usr/local/phenix-1.10.1-2155/modules/cctbx_project/libtbx/easy_run.py", line 160, in __init__ close_fds=not subprocess.mswindows) File "/usr/local/phenix-1.10.1-2155/base/lib/python2.7/subprocess.py", line 710, in __init__ errread, errwrite) File "/usr/local/phenix-1.10.1-2155/base/lib/python2.7/subprocess.py", line 1223, in _execute_child self.pid = os.fork() OSError: [Errno 12] Cannot allocate memory -- 卢作焜南开大学新生物站A202 Lu Zuokun, Ph.D. Candidate College of Life Science, Nankai University

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Re: [phenixbb] Self Rotation Function
by Sharan Karade 05 May '16

05 May '16

Thank you for your valuable Edward, Patrick, Francis. I will try with your suggestions. And let you know the results. On 4 May 2016 20:03, "Edward A. Berry" <BerryE(a)upstate.edu> wrote: On 05/04/2016 10:17 AM, Patrick Loll wrote: > You won’t see peaks in the self-rotation function unless the AU contains > non-crystallographic rotational symmetry, which frequently is not the case > (just because you have multiple copies of your protein in the AU does not > imply that they are arranged in any specific, symmetric manner). And even > if there is rotational NCS, if the axis of rotation is parallel to a > crystal symmetry operator, the effect of the NCS will be masked. So > everything may be working as it should. > > If you’re not certain if you have the program working correctly, then I > suggest that you find a structure in the PDB that contains rotational NCS, > download the structure factors, and calculate the self-rotation map, as a > positive control. > > Try bacterioferritin (in a low-symmetry space group) or GroEL ! > On 4 May 2016, at 12:10 AM, Sharan Karade <sharankarade(a)gmail.com> wrote: >> >> Hello everyone, >> >> i am working on data set which has resolution of 2.8 A >> space group C2, the protein have 394 a a . when i estimate Mathews >> coefficient it shows four to five molecules in asymmetric unit. when i try >> to get self rotation function Map by default parameter (10A-3A and 25 >> radius of integration) i was not getting any peak at all 180, 90, 120, 60. >> Or radius of integration affect the results. >> >> Can anybody please help me to sort out with this problem, welcome for >> suggestions, thanks in advance. >> >> -- >> Sharan >> C/O Dr. J V Pratap >> Senior Research Fellow, >> CSIR-Central Drug Research Institute, >> Lucknow >> >> >> >> _______________________________________________ >> phenixbb mailing list >> phenixbb(a)phenix-online.org >> http://phenix-online.org/mailman/listinfo/phenixbb >> Unsubscribe: phenixbb-leave(a)phenix-online.org >> > > > > > --------------------------------------------------------------------------------------- > Patrick J. Loll, Ph. D. > Professor of Biochemistry & Molecular Biology > Director, Biochemistry Graduate Program > Drexel University College of Medicine > Room 10-102 New College Building > 245 N. 15th St., Mailstop 497 > Philadelphia, PA 19102-1192 USA > > (215) 762-7706 > pat.loll(a)drexelmed.edu > > > _______________________________________________ > 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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