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Refinement using data with pseudo translational symmetry
by Bret Wallace 18 Mar '12

18 Mar '12

To all, First I apologize for the long email, but I wont to make sure that I give enough information to describe the problem. I have been working on a structure of two proteins in complex with each other (one forms a homodimer, with each monomer bound to 1 monomer of the other protein), using data, that according to phenix.xtriage contains pseudo translational symmetry (output pasted below). I have done a lot of searching of both the phenixBB and ccp4BB regarding solutions to this problem, but unfortunately most responses seem to be directed at resolving issues with MR. I have successfully performed MR using both phenix phaser, ccp4 phaser (the most updated version), as well as molrep. The issue arises upon structure refinement, where my Rwork and Rfree are essentially stuck at 28 and 33, respectively. I have built the entire structure, including ligands, except for any solvent molecules. Here are the details for the data/structure: SG: P212121 Cell: 72 124 175 90 90 90 Res: 50-2.8 Patterson analyses ------------------ Largest Patterson peak with length larger than 15 Angstrom Frac. coord. : 0.155 0.000 0.500 Distance to origin : 87.222 Height (origin=100) : 34.517 p_value(height) : 6.739e-04 The reported p_value has the following meaning: The probability that a peak of the specified height or larger is found in a Patterson function of a macro molecule that does not have any translational pseudo symmetry is equal to 6.739e-04. p_values smaller than 0.05 might indicate weak translational pseudo symmetry, or the self vector of a large anomalous scatterer such as Hg, whereas values smaller than 1e-3 are a very strong indication for the presence of translational pseudo symmetry. Xtriage notes that the if the PTS is crystallographic, that C2221 is a possible SG (x+1/6, y, z+1/2). However, neither XDS or HKL picks orthorhombic C, and the indexing/integrating doesn't work if I force it. I should also not there is no twinning detected by either xtriage or twinning servers. I have done a number of things to try to resolve this: -rescaling in lower symmetry (P21 and P1) -rescaling in the PG P222 and letting the MR program decide the proper space group -shifting origin and re-refining -a number of different refinement protocols (TLS, optimized weights/adp, simulated annealing, several cycles of rigid body, etc.) I have used HKL2000 and XDS to index/integrate/scale the data, both yield the same results, with slightly different completeness and Rmerge values, but refining with either gives similar R factor values. Does any know of any other possible things I should try to refine this data? I am happy to provide additional information upon request. Thanks in advance for any help! Bret

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selectively remove bond length restraints on atoms
by Maxime Cuypers 15 Mar '12

15 Mar '12

hello, What is the best way to selectively remove bond length restraints on some selected atoms for phenix.refine? i found the commands for a .param file: refinement { geometry_restraints.remove { angles = None dihedrals = None chiralities = None planarities = None } } but no bond length command in the manual online. http://www.phenix-online.org/version_docs/dev-283/refinement.htm otherwise there is the commands refinement { geometry_restraints.edit { bond { action= *delete change atom_selection_1= (selection1 here) atom_selection_2= (selection2 here) distance_ideal= None } } } is it a good way to deal with the problem ? thanks in advance for your help. Maxime

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crystal packing pattern
by bsubedi＠btk.fi 15 Mar '12

15 Mar '12

Hi All, Could someone help me with a program/tool to see the pattern of protein packing in the crystal. I would like to make comparative study between regions of the protein in two different chains and if crystal packing has some effect on conformational alteration. Kind regards, World

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Reminder: BCA/CCP4 Summer School 2012
by Airlie McCoy 15 Mar '12

15 Mar '12

This is a reminder that applications are now open for the BCA/CCP4 Summer School in Protein Crystallography to be held at Diamond (UK) from Tuesday 28th August to Sunday 2nd September 2012. Applications close 1st May 2012. The course is suitable for PhD students in macromolecular crystallography who started in or before October 2011, and postdocs new to macromolecular crystallography. Please note that references from supervisors are also due by 1st May 2012, so don't leave your application until the last minute! For more information see: http://www.diamond.ac.uk/Home/Events/BCA-Summer-School-2012.html Application form: http://www.diamond.ac.uk/Home/Events/BCA-Summer-School-2012/Application-Pag…

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Transfer to new computer
by Colin Levy 15 Mar '12

15 Mar '12

Hi, Is it possible to transfer Phenix along with it's archive to a new computer? I have a fresh install of Phenix on the new machine and a copy of all the original files and folders from the old machine but cant figure how to point Phenix to the correct place. Thanks Colin

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March 15, 2012 deadline- User proposal submission for Collaborative Crystallography at BCSB
by Banumathi Sankaran 14 Mar '12

14 Mar '12

Dear Users, The deadline for May/June 2012 Collaborative Crystallography proposals will be *Mar 15, 2012. * ------------------------------------------------------------------------ Through the Collaborative Crystallography Program (CC) at the Advanced Light Source (ALS), scientists can send protein crystals to Berkeley Center for Structural Biology (BCSB) staff researchers for data collection and analysis. The CC Program can provide a number of benefits to researchers: * Obtain high quality data and analysis through collaborating with expert beamline researchers; * Rapid turn around on projects; and * Reduced travel costs. To apply, please submit a proposal through the ALS General User proposal review process for beamtime allocation. Proposals are reviewed and ranked by the Proposal Study Panel, and beamtime is allocated accordingly. BCSB staff schedule the CC projects on Beamlines 5.0.1 and 5.0.2 to fit into the available resources. Only non-proprietary projects will be accepted. As a condition of participation, BCSB staff researchers who participate in data collection and/or analysis must be appropriately acknowledged - typically being included as authors on publications and in PDB depositions. Please consult the website for additional information at: http://bcsb.als.lbl.gov/wiki/index.php/Collaborative_Crystallography ------------------------------------------------------------ ----------------------------- How To Apply: To learn more, go to: http://www.als.lbl.gov/als/quickguide/becomealsuser.html To submit a proposal, go to: http://alsusweb.lbl.gov/. Scroll down to "*Structural Biology beamlines (includes protein SAXS)*" and click on "New Proposal." Enter your proposal information, with attention to the following details: * For question 3/First choice, select "5.0.1 (Monochromatic);" for question 3/Second choice, select "5.0.2 (MAD)." * Check box (yes) in response to question (7) "Do you want collaborative crystallography (beamline 5.0.1 or 5.0.2 only) * In question 4, please describe a specific research project with a clear end point. In order to request CC time for May/June 2012 allocation period, proposals must be submitted by *March 15, 2012.* The deadline for CC proposals for the time period July/August 2012 will be May 15, 2012. Regards, Banumathi Sankaran

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David Sayre
by Paul Adams 12 Mar '12

12 Mar '12

On behalf of the Phenix development team: We regret deeply the passing of David Sayre on Feb. 23, 2012. David Sayre made profound contributions to crystallography and scientific computing that continue to have a major impact decades later. An obituary summarizing his many achievements was posted by Physics Today (http://www.physicstoday.org/1.2732466). In crystallography, Sayre’s fundamental insight into the implications of the atomic nature of crystal structures and the relationships between crystallographic structure factors allowed him to develop in 1952 the brilliantly simple Sayre equation relating each structure factor to all other structure factors. The Sayre equation has had a well-known yet greatly under-appreciated significance in small-molecule crystallography, both in its original form and in the equivalent probabilistic forms implemented later as part of direct methods. These methods have profoundly affected macromolecular crystallography in the last decade because of their astounding power for determination of heavy-atom substructures. The use of direct methods has made possible solution of the positions of as many as 160 selenium atoms in large macromolecular structures. To appreciate the feat that this represents, it is useful to consider that many macromolecular crystallographers were initially hesitant to use the seleno-methionine approach at all for structures that had more than about 10 selenium atoms for fear that the substructure could not be solved. Sayre’s recent work on phasing X-ray diffraction data from single large objects such as a yeast cell and single small objects such as a single protein molecule was groundbreaking in a different way. This work is revolutionary because of its boldness, and because of the elegantly simple approach to phase determination that Sayre developed. Once again Sayre took a fundamental real-space feature of the diffraction image and used it to obtain phase relationships. In this case the diffraction forms a continuous pattern from a single object, and the feature is the lack of contrast outside of the object. While the idea of using a mask of the object (the “support”) to define phases has been used for some time in many contexts, it was far from obvious that this could be done with a single cell or with a single protein molecule. Sayre and his colleagues systematically showed theoretically and then experimentally that each step in this process can be carried out and that the required signal can be extracted to obtain an X-ray image of microdots and later even a yeast cell. Others have followed up his ideas for phasing data from a single protein molecule. This work was of fundamental and transforming importance because few would have believed that the ideas were remotely feasible, and now they have a sound theoretical basis and experimental demonstrations, allowing anyone to think of new and powerful ways to use these approaches. The breadth of Sayre's intellectual spectrum reached far beyond crystallography. He was also a member of the IBM team that developed the original Fortran compiler, the first high-level programming tool (see http://www.ibm.com/ibm100/us/en/icons/fortran/team/ for more details). Currently, 55 years after the first commercial release of Fortran, this language is still in wide use. The history of crystallographic computing, and scientific computing in general, cannot be separated from the success of Fortran, made possible by the amazing IBM team that included Sayre. In spite of his great accomplishments, David Sayre was modest and approachable in person, and he was generous in sharing credit with his colleagues. He will be greatly missed. -- Paul Adams Deputy Division Director, Physical Biosciences Division, Lawrence Berkeley Lab Division Deputy for Biosciences, Advanced Light Source, Lawrence Berkeley Lab Adjunct Professor, Department of Bioengineering, U.C. Berkeley Vice President for Technology, the Joint BioEnergy Institute Laboratory Research Manager, ENIGMA Science Focus Area Building 64, Room 248 Tel: 1-510-486-4225, Fax: 1-510-486-5909 http://cci.lbl.gov/paul Lawrence Berkeley Laboratory 1 Cyclotron Road BLDG 64R0121 Berkeley, CA 94720, USA. Executive Assistant: Louise Benvenue [ LBenvenue(a)lbl.gov ][ 1-510-495-2506 ] --

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phenix.elbow problem
by Simon Kolstoe 12 Mar '12

12 Mar '12

Hi there, Who's the best person to talk to when phenix.elbow is not assigning correct geometry to a molecule? Thanks, Simon --------------------------------------------------------------- Dr Simon Kolstoe Laboratory for Protein Crystallography Wolfson Drug Discovery Unit University College London Rowland Hill Street, London NW3 2PF Tel: 020 7433 2765 http://www.ucl.ac.uk/~rmhasek ---------------------------------------------------------------

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error after adp refinement
by Christian Roth 10 Mar '12

10 Mar '12

Dear Phenix Team, I started a refinement with anisotropic adp and weight optimization and directly after the optimization step an error appeared which never appeared befor for me. The previous steps of mask optimization and xyz refinement worked well. Best Regards Christian AssertionError : Traceback: File "/userdata-2/christian/phenix- dev-979/cctbx_project/libtbx/thread_utils.py", line 229, in run return_value = self._target(self._args, self._kwargs, self._c) File "/userdata-2/christian/phenix- dev-979/cctbx_project/libtbx/runtime_utils.py", line 72, in __call__ result = self.target() File "/userdata-2/christian/phenix- dev-979/phenix/phenix/refinement/runtime.py", line 68, in __call__ call_back_handler=callback) File "/userdata-2/christian/phenix- dev-979/phenix/phenix/refinement/command_line.py", line 97, in run call_back_handler=call_back_handler) File "/userdata-2/christian/phenix- dev-979/phenix/phenix/refinement/driver.py", line 1494, in run ncs_manager = self.ncs_manager) File "/userdata-2/christian/phenix- dev-979/phenix/phenix/refinement/strategies.py", line 1046, in refinement_machine h_params = h_params) File "/userdata-2/christian/phenix- dev-979/cctbx_project/mmtbx/refinement/adp_refinement.py", line 212, in __init__ nproc = nproc) File "/userdata-2/christian/phenix- dev-979/cctbx_project/mmtbx/refinement/adp_refinement.py", line 389, in __init__ compute_gradients=False).target_work()) Platform info: __FILE__ = /net/longnose/scratch2/phenix/phenix- dev-979/cctbx_project/boost_adaptbx/meta_ext.cpp __DATE__ = Feb 7 2012 __TIME__ = 02:05:24 __i386__ __linux __GNUC__ = 3 __GNUC_MINOR__ = 4 __GNUC_PATCHLEVEL__ = 2 boost::python::cxxabi_cxa_demangle_is_broken(): false __GXX_WEAK__ = 1 __VERSION__ = 3.4.2 20041017 (Red Hat 3.4.2-6.fc3) FE_INEXACT = 32 FE_DIVBYZERO = 4 FE_UNDERFLOW = 16 FE_OVERFLOW = 8 FE_INVALID = 1 FE_ALL_EXCEPT = 61 BOOST_LIB_VERSION = 1_48 PY_VERSION = 2.7.2 PYTHON_API_VERSION = 1013 sizeof(bool) = 1 sizeof(short) = 2 sizeof(int) = 4 sizeof(long) = 4 sizeof(std::size_t) = 4 sizeof(void*) = 4 sizeof(long long) = 8 sizeof(float) = 4 sizeof(double) = 8 sizeof(long double) = 12 sizeof(boost::int32_t) = 4 sizeof(boost::uint32_t) = 4 sizeof(wchar_t) = 4 __PTRDIFF_TYPE__ Py_USING_UNICODE sizeof(PY_UNICODE_TYPE) = 2 gnu libc version: 2.10.1 BOOST_ADAPTBX_TYPE_ID_SIZE_T_EQ_UNSIGNED os.name: posix sys.platform: linux2 sys.byteorder: little platform.platform(): Linux-2.6.31-23-generic-pae-i686-with-debian-squeeze-sid platform.architecture(): ('32bit', 'ELF') floating_point_exceptions.division_by_zero_trapped: False floating_point_exceptions.invalid_trapped: False floating_point_exceptions.overflow_trapped: False number of processors: 8 Memory total: 25,405,636,608 Memory free: 20,305,633,280 import thread: OK "hello" = ['h', 'e', 'l', 'l', 'o'] u"hello" = ['h', '\x00', 'e', '\x00', 'l', '\x00', 'l', '\x00', 'o', '\x00'] u"\u00C5" = ['\xc5', '\x00'] as utf-8 = ['\xc3', '\x85'] LATIN CAPITAL LETTER A WITH RING ABOVE = Å

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Calculating Bijvoet difference Fourier map
by John Rose 08 Mar '12

08 Mar '12

Hi, I am some what new to PHENIX and using the Mac GUI. I want to compute a Bijvoet difference Fourier map. Any help would be appreciated. John Rose

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