- phenixbb - phenix-online.org

PPC binaries?
by Marcelo Carlos Sousa 05 Apr '10

05 Apr '10

Is Phenix no longer supported on Mac PPC? ____________________________________________ Marcelo C. Sousa, Ph.D. Department of Chemistry and Biochemistry Cristol Chemistry Building. Room 100 215 UCB University of Colorado at Boulder Boulder, CO 80309 Phone: (303) 735 4341 Fax: (303) 492 5894

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(no subject)
by Prof Jennifer Martin (IMB) 04 Apr '10

04 Apr '10

The protein crystal structure I am refining has a redox modification: cysteine sulfenic acid (S-hydroxy cysteine). How do I go about including parameters for this modification in phenix refine? I have found parameters on HIC-UP (under CSO) but these are for XPLOR/ CNS. Many thanks in advance for suggestions, Jenny Martin University of Queensland

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Torsion angels refinement question
by Peter Grey 04 Apr '10

04 Apr '10

Dear Phenix users, I try to refine a big complex at low resolution. I am a little confused about the syntax of using torsion angels gradient-driven refinement. Is it now the default for individual sites refinement instead of cartesian ? If not, should I add : sites.Torsion_angles=all for example ? Could you shed some light on this, Thank you, -- Peter

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Optimizing the Geometry Weight for a 2.76 A structure
by Sam Stampfer 03 Apr '10

03 Apr '10

Hi, I'm refining a 2.76 A structure and need help optimizing the refinement weight on geometry. When I refine at the default refinement weight (wxc = 0.5), phenix seems to generate a much poorer structure (both geometrically AND by Rfree value) relative to lower wxc values which put a stronger weight on geometry. I am trying to pick the best structure to use for my next round of rebuilding. The R-stats and condensed molprobity stats are listed below (at the end of this email). I have a few questions regarding this structure and those stats: 1. What is the relevance of having a LOW difference between Rfree and Rwork? My structure seems to have a higher than expected Rwork value relative to Rfree (aren't they supposed to differ by 0.05 or so, instead of the 0.03 observed in my structure?) Additionally, as I refine at lower wxc values (more weight on geometry) I get an increased Rwork value with an equal or decreased Rfree (relative to the refinement at a higher wxc value). Does that mean my structure is better or worse? 2. How can I judge the output from my refinement? I have looked at Rwork, Rfree, and the molprobity clashscore and overall score values. I included them below, at the end of this email. How do I tell which the best refinement is? Which one would you suggest? I thought the best was wxc = 0.1 since the R-work and Rfree aren't changed much from the start values but the geometry is far better. 3. How do I optimize the weight on geometry in refinement? My PI said that phenix can do it but not for twinned structures (my structure is twinned). Can the new version of phenix do weight optimization for twinned structures? How? If not, what's the best way for me to do it manually? As always, thanks immensely for all your help! -Sam All have the same values for: Start R-work = 0.2002, R-free = 0.2376 *wxc = 0.01 *Final R-work = 0.2104, R-free = 0.2378 Molprobity Clashscore: 19.46 Molprobity Score: 2.29 *wxc = 0.05 *Final R-work = 0.2049, R-free = 0.2377 Molprobity Clashscore: 20.96 Molprobity Score: 2.38 *wxc = 0.1 *Final R-work = 0.2010, R-free = 0.2388 Molprobity Clashscore: 23.50 Molprobity Score: 2.54 *wxc = 0.2 *Final R-work = 0.1969, R-free = 0.2399 Molprobity Clashscore: 27.15 Molprobity Score: 2.79 *wxc = 0.3 *Final R-work = 0.1945, R-free = 0.2411 Molprobity Clashscore: 30.76 Molprobity Score: 2.97 *wxc = 0.4 *Final R-work = 0.1930, R-free = 0.2420 Molprobity Clashscore: 34.54 Molprobity Score: 3.11 *wxc = default (0.5) *Final R-work = 0.1918, R-free = 0.2429 Molprobity Clashscore: 37.73 Molprobity Score: 3.22

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Re: [phenixbb] Optimizing the Geometry Weight for a 2.76 A structure
by det102＠uoxray.uoregon.edu 02 Apr '10

02 Apr '10

Dear Phil, I don't have access to vol 277 of Met Enz here, which is sad since I wrote a chapter in the thing, so I can't comment on Axel's exact words. I agree that the uncertainty in the ability of the free R estimate based on a subset of reflections to predict the mean of the free R calculated from all possible test sets of that size is proportional to 1/N. My point is that the pdf of the difference of two random variables is not the same as the pdf of either of them. You have to know the coupling between them to decide if the difference between them has greater or less precision than the individual variable. For example, let's assume two measurements with a precision of 1% but the difference in the two measurements is 0.5%. This small difference can be significant if the causes of the uncertainties are systematic. The "errors" would cancel out. I believe the fluctuations in free R estimate due to the small size of the test set are due to the particular indices in the test set and therefore mainly systematic. The intensities of some reflections may have been measured better than others and your test set may happen to be more enriched with those, resulting is a slightly lower free R estimate. Since the test set is always the same during refinement the benefit of this enrichment (or detriment if you were unlucky) will be subtracted out when you compare the two free R estimates during your optimization. I expect the difference between two free R estimates (using the same test set) will be a more precise indicator of the true change in free R than either estimate is in predicting the free R itself. Dale Phil Jeffrey wrote: > Although I am totally unclear why the form of the equation, which is > just counting/Poisson statistics, doesn't also apply to the uncertainty > of calculating the average percentage deviation over a test set of size > N. For example a test set of N=1000 could be regarded as 100 different > test sets of size N=10, and I think it's likely that the distribution of > R-free for these 100 mini test sets would be Poisson in form centered > around the R-free for the superset N=1000. > > So, since the change in |Fo-Fc| for each reflection doesn't simply scale > with wxc in structure refinement nor does it inevitably decrease for > every reflection on structure improvement, the change in R-free for any > given change in structure should be related to N in the form of the > equation given, so does reflect the s.d. of R-free as an estimate for > structure improvement. > > No ? > > If not, then I misinterpreted what Brunger mean on p.394 of his 1997 Met > Enz paper because that's certainly what it read like. > > Phil > > det102(a)uoxray.uoregon.edu wrote: >> >> That uncertainty is not quite the same thing. What you describe >> is the uncertainty in the free R due to the small sampling size of >> the test set. It is the spread of free R's obtained when different >> test sets are chosen for the same project and circumstances, and is >> useful when comparing free R's calculated using different test sets, >> or, heaven forbid, trying to compare free R's from different crystals.

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map grid size
by Sean Gay 02 Apr '10

02 Apr '10

Does anyone know if there is a way to increase the map sampling rate for Phenix fofc and 2fofc maps? I want to make a figure for publication in PyMOL and the map_double command helps a bit, but i'd still like more points on the map grids. Sean Sean C. Gay, PhD Postdoctoral Scholar Skaggs School of Pharmacy and Pharmaceutical Sciences University of California, San Diego 9500 Gilman Dr. #0703 La Jolla, CA 92093 Tel. (858)822-7804 Fax. (858)246-0089 Email. scgay(a)ucsd.edu

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Double stranded DNA restraints?
by Rajagopalan, Senapathy 02 Apr '10

02 Apr '10

Hi Everyone, Is there a way to force phenix (autobuild) into building a contiguous double stranded DNA. Currently, when I am solving a protein-DNA complex using SAD data: 1) its not recognizing that DNA needs to be double stranded, so it is fitting one of the strands correctly (at least part of it), but the other strand is in the protein density region. 2) It breaks down each of the strand. So it is not fitting as a contiguous 30 mer but instead a 10 mer, two 6 mers and a 8 mer. Thanks Sena Methodist. Leading Medicine. Recognized by U.S.News & World Report as an "Honor Roll" hospital Named to FORTUNE magazine's "100 Best Companies to Work For" list five years in a row Designated as a Magnet hospital for excellence in nursing Visit us at methodisthealth.com Follow us at twitter.com/MethodistHosp and www.facebook.com/methodisthospital ***CONFIDENTIALITY NOTICE*** This e-mail is the property of The Methodist Hospital and/or its relevant affiliates and may contain restricted and privileged material for the sole use of the intended recipient(s). Any review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender and delete all copies of the message. Thank you.

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Secondary structure restraints for nucleic acids
by Peter Grey 02 Apr '10

02 Apr '10

Dear developers, Does the new mechanism of secondary structure restraints apply to nucleic acids as well ? Are the average bond distances similar and does DSSP works well with RNA/DNA ? Thank you in advance for clarifying this issue, Peter.

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Installation problem
by Tatsuya Kaminishi 02 Apr '10

02 Apr '10

Dear Phenix BB When I tried to install the latest binary version (1.6.1), the "install" script always stopped and dumped an error message as follows: ----- /software/PHENIX/phenix-installer-1.6.1-357/bin/install-from-binary: line 347: 10964 Floating point exception$PHENIX_BUILD/base/bin/python $PHENIX_LOC/cctbx_project/libtbx/configure.py -- current_working_directory="$PHENIX_BUILD" $PHENIX_COMPONENTS >> $PHENIX_LOG/binary.log 2>&1 Error configuring: see /software/PHENIX/phenix-installer-1.6.1-357/ build-binary/intel-linux-2.6-x86_64/lupus/log/binary.log for details ----- And this "binary.log" file looks like this; ========== . . After many lines... . ./reduce/comment_out_carboxylate_H_v2.3.pl ./reduce/Makefile ./reduce/libtbx_refresh.py ========== This never happened when I installed version 1.6-289. Could anybody out there tell me how I can get around this? Or anything important is missing? The system I'm using is: Linux crux 2.6.16.60-0.27-smp #1 SMP Mon Jul 28 12:55:32 UTC 2008 x86_64 x86_64 x86_64 GNU/Linux SUSE Linux Enterprise Desktop 10 (x86_64) VERSION = 10 PATCHLEVEL = 2 Thank you very much for your help in advance! Best regards, kami Tatsuya KAMINISHI, Ph.D. Fucini Laboratory Institute for Organic Chemistry and Chemical Biology Johann Wolfgang Goethe University Max-von-Laue-Strasse 7, N160/B413 D-60438 Frankfurt am Main, Germany Tel: +49 69 798-29165 Fax: +49 69 798-29268 Web: http://user.uni-frankfurt.de/~joharms/akfucini/

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Restraints on dihedrals in phenix.refine
by Gregers Rom Andersen 02 Apr '10

02 Apr '10

hi phenix-bb in the standard phenix.refine scripts there are options for adding user defined restraints on bonds and angles, but not on dihedrals. Is this currently possible in phenix.refine? One application would be to restrain the phi-psi angles of a low resolution structure to phi-psi angles from a high-res structure of the same protein, an option previously made possible for xplor in the USF program XPLO2D gregers Gregers Rom Andersen Associate professor Department of Molecular Biology University of Aarhus Gustav Wiedsvej 10C DK8000 Aarhus C phone +45 89425024 fax +45 86123178 www.bioxray.au.dk/gra

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Cadmium missing atoms
by Kristin Sutton 31 Mar '10

31 Mar '10

Hello- I am refining a structure with 2 cadmium ions present. From the extensions menu in coot, I clicked on modeling >> residues with missing atoms, and both Cadmium ions came up in that list. The density surrounding these atoms is also strange, positive density right in the middle of the atom, negative density surrounding the whole atom. How do I make sure these are being refined correctly? Thank you in advance, Kristin ******************************************************************** Kristin A. Sutton Graduate Student University of Buffalo Department of Structural Biology Hauptman-Woodward Medical Research Institute 700 Ellicott Street Buffalo, NY 14203 P: (716)898-8683 F: (716)898-8600 E: ksutton(a)hwi.buffalo.edu

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Phenix version 1.6.1 released
by Paul Adams 31 Mar '10

31 Mar '10

The Phenix developers are pleased to announce that version 1.6.1 of Phenix is now available. Binary installers for Linux, and Mac OSX platforms are available at the download site: http://phenix-online.org/download/ Just some of the new features in this version (1.6.1) are: - Fast automated rotamer fixing in phenix.refine - Use of atomic charge in calculation of scattering factors - New Graphical User Interfaces for phenix.superpose_pdbs, phenix.get_cc_mtz_mtz, phenix.get_cc_mtz_pdb, and phenix.fmodel - Consolidated validation tool in GUI - New map calculation tool, phenix.maps (also used in GUI) - Rapid loading of structures in GUI selection editor - Improved geometry restraints to maintain amino acid rotameric states - Alpha version of secondary structure restraints - Automated secondary structure analysis with KSDSSP (code from UCSF CGL) For a full list of changes see: http://www.phenix-online.org/documentation/CHANGES Please note that there is a new publication that should be used to cite use of Phenix: PHENIX: a comprehensive Python-based system for macromolecular structure solution. P. D. Adams, P. V. Afonine, G. Bunkóczi, V. B. Chen, I. W. Davis, N. Echols, J. J. Headd, L.-W. Hung, G. J. Kapral, R. W. Grosse-Kunstleve, A. J. McCoy, N. W. Moriarty, R. Oeffner, R. J. Read, D. C. Richardson, J. S. Richardson, T. C. Terwilliger and P. H. Zwart. Acta Cryst. D66, 213-221 (2010). 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 Acting Division Director, Physical Biosciences Division, Lawrence Berkeley Lab Adjunct Professor, Department of Bioengineering, U.C. Berkeley Vice President for Technology, the Joint BioEnergy Institute Head, Berkeley Center for Structural Biology 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: Patty Jimenez [ PAJimenez(a)lbl.gov ] [ 1-510-486-7963 ] --

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Re: [phenixbb] Citation for xtriage
by Folmer Fredslund 30 Mar '10

30 Mar '10

Dear Mark, On 30 March 2010 19:30, Dr. Mark Mayer <mayerm(a)mail.nih.gov> wrote: > > I'm writing up some results for which we used phenix.xtriage to screen xtals > for twin fraction and would like to know if there is a paper we could/should > cite? > > At the time this work was done we were not using the rest of the phenix > suite for refinement (we are now!). > Going to the phenix FAQS (http://www.phenix-online.org/documentation/faqs.htm#anch2) it would be PHENIX: a comprehensive Python-based system for macromolecular structure solution. P. D. Adams, P. V. Afonine, G. Bunkóczi, V. B. Chen, I. W. Davis, N. Echoo ls, J. J. Headd, L.-W. Hung, G. J. Kapral, R. W. Grosse-Kunstleve, A. J. McCoy, N. W. Moriarty, R. Oeffner, R. J. Read, D. C. Richardson, J. S. Richardson, T. C. Terwilliger and P. H. Zwart. Acta Cryst. D66, 213-221 (2010). Or maybe the developers prefer you cite the CCP4 newletters listed at: http://www.phenix-online.org/documentation/xtriage.htm#anch24 Hope this helps, Folmer Fredslund

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Citation for xtriage
by Dr. Mark Mayer 30 Mar '10

30 Mar '10

I'm writing up some results for which we used phenix.xtriage to screen xtals for twin fraction and would like to know if there is a paper we could/should cite? At the time this work was done we were not using the rest of the phenix suite for refinement (we are now!). Thanks, Mark --

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shaking a PDB without introducing clashes
by Francois Berenger 30 Mar '10

30 Mar '10

Hello, I recently used "phenix.pdbtools modify.sites.shake=..." in order to have some data from 0.1 to 5A. away from the true structure in order to test some scripts. I think this introduced clashes in the "shaken" PDBs I got. Is there a tool/way to avoid this? Best regards, Francois.

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RMSD Dihedrals
by J. Fleming 30 Mar '10

30 Mar '10

Hi all, I'm working on a ~3 angstrom structure of a protein with approximately 800 residues. The structure is mostly helical with interspersed turns. I've been using Phenix exclusively for the refinements and have a model that I believe to be pretty good with the exception of the dihedrals (see attached). I've looked at and employed some of the general suggestions for low resolution structures here: http://strucbio.biologie.uni-konstanz.de/ccp4wiki/index.php/Refinement#Refi… I tried using "discard_psi_phi=False" but it only resulted in a change dihedrals of +0.10 with minimal changes to Ramachandran outliers. I'm unsure how to proceed and would love to hear any thoughts/opinions/suggestions. Thanks for all the help! -Jon

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Re: [phenixbb] h_bonds restraints
by Maia Cherney 28 Mar '10

28 Mar '10

Hi Boaz, The problem is with the distance between 2 waters and not the Mg-water distance. These 2 waters belong to the Mg coordination, still they should be at a h_b distance from one another. I got around this problem by setting my custom restraints, but I think the program should take care of this. Maia Boaz Shaanan wrote: > Hi Maia, > > Can I make two comments concerning the distance restraints that you're > struggling with: > 1) I don't know the resolution your structure, nor do I know the way > Phenix treats the distance restraints internally, but I guess it's > similar to the way it is in CNS. That is, there is a value for the > restaint (2.1-2.2 A in your case) and there should be a number for the > tolerance of that distance (or its s.d.) which the user can decide on, > depending on the resolution. It is possible that Phenix is clever > enough to figure out this tolerance from the resolution and the > complete set of restraints, I'm not sure. > > 2) I wouldn't worry too much about the validation (as in fact Pavel > has alluded to). If your water molecules in the Mg+2 coordination > sphere "insist" on being closer to the metal than you expect, despite > all your efforts, then this is it. The RCSBpeople and validation > process should know about standard and deviation and resolution. In > the worst case your deposited structure will have a comment/remark put > in your deposited PDB saying perhaps that the Mg-water distances are > shorter by that much from the norm. > > That's my 2p worth thought. > > Cheers, > > Boaz > > ----- Original Message ----- > From: Maia Cherney <chern(a)ualberta.ca> > Date: Sunday, March 28, 2010 14:14 > Subject: Re: [phenixbb] h_bonds restraints > To: PHENIX user mailing list <phenixbb(a)phenix-online.org> > > > Hi Pavel, > > > > I have waters that are part of the Mg2+ coordination. They > > should be at > > ~2.1A from Mg2+. At the same time, they should be at a hydrogen- > > bonding > > distance from each other (minimum 2.2A otherwise the validation > > at the > > PDB complains). The two waters after refinement without > > restraints had > > closer (2.12A) distance between them, so I managed to restrain > > the > > distance to 2.23A using pdb_interpretation. But my question was, > > should > > not the refinement automatically restrain close distances > > between any > > atoms, including waters? (By the way, I picked them manually). > > > > Maia > > > > Pavel Afonine wrote: > > > Hi Maia, > > > > > > I'm not sure I understand the question. If you have that > > specific > > > water in your structure already (and you run phenix.refine > > with > > > "ordered_solvent=false"), then changing the > > h_bond_min_mac or > > > h_bond_min_sol will not change anything since these parameters > > are > > > used in water update. > > > > > > However, if you are at the stage of water picking and the > > distance > > > between Mg2+ and prospective water peak is 2.2A then the water > > will be > > > placed there (providing that the corresponding peak satisfies > > the > > > other criteria). > > > > > > Could you please explain what exactly the problem is, and then > > I will > > > try my best to give you the solution? > > > > > > Thanks! > > > Pavel. > > > > > > > > > On 3/27/10 5:23 PM, Maia Cherney wrote: > > >> Hi Pavel, > > >> what is h_bond_min_mac and h_bond_min_sol. > > >> > > >> which one should I change to 2.2 so that it will not affect > > the > > >> coordination distances of Mg2+ (around 2A)? > > >> > > >> Maia > > >> > > >> Pavel Afonine wrote: > > >>> Hi Maia, > > >>> > > >>>> I have done the things that you suggested, > > >>> > > >>> great! > > >>> > > >>>> and I have all the restraints for the Mg2+ and I see those > > 2 > > >>>> waters, but they are at 2.12A distance. > > >>> > > >>> Are these two waters located in the centers of corresponding > > density > > >>> peaks? If this is the case then I don't see the subject of > > your > > >>> worries. If this is not the case (these waters are off the > > peaks) > > >>> then edit the file that defines restraints for water-Mg2+ > > interactions.>>> > > >>>> I think there should be some general restraints that should > > keep > > >>>> h_bonds at least at > 2.2A. > > >>> > > >>> Yes. You wrote it yourself in your previous email: > > >>> > > >>> h_bond_min_mac = 1.8 > > >>> h_bond_min_sol = 1.8 > > >>> h_bond_max = 3.2 > > >>> > > >>> Just change the values to what you like! > > >>> > > >>>> That is why I asked you about those defaults (1.8A etc). > > Why are > > >>>> they at 1.8A? Should not they be at least at 2.2A? > > >>> > > >>> Honestly, I don't remember why I put these values (this is > > pretty > > >>> old code in phenix.refine that I wrote several years ago). > > All I > > >>> recall is that I had a reason for this. I probably need to > > run > > >>> through the whole PDB and see how the density peaks (actual, > > >>> residual, omit-residual) are distributed w.r.t. > > macromolecule, and > > >>> write it somewhere for the future reference. This could be a > > project > > >>> for a few weeks, but it will definitely yield a rock-solid > > >>> conclusion about "good" distances. Meanwhile feel free to > > edit the > > >>> available parameters. > > >>> > > >>> By the way, this is what CNS is using: > > >>> > > >>> {* minimum distance between water and any atom *} > > >>> {===>} min=2.6; > > >>> {* maximum distance between water and any atom *} > > >>> {===>} max=4.0; > > >>> > > >>> {* minimum hydrogen bonding distance between water and O or > > N *} > > >>> {===>} hmin=2.0; > > >>> {* maximum hydrogen bonding distance between water and O or > > N *} > > >>> {===>} hmax=3.2; > > >>> > > >>> Pavel. > > >>> > > >>> _______________________________________________ > > >>> phenixbb mailing list > > >>> phenixbb(a)phenix-online.org > > >>> http://phenix-online.org/mailman/listinfo/phenixbb > > >>> > > >>> > > >> _______________________________________________ > > >> phenixbb mailing list > > >> phenixbb(a)phenix-online.org > > >> http://phenix-online.org/mailman/listinfo/phenixbb > > > _______________________________________________ > > > phenixbb mailing list > > > phenixbb(a)phenix-online.org > > > http://phenix-online.org/mailman/listinfo/phenixbb > > > > > > > > _______________________________________________ > > phenixbb mailing list > > phenixbb(a)phenix-online.org > > http://phenix-online.org/mailman/listinfo/phenixbb > > > > > Boaz Shaanan, Ph.D. > Dept. of Life Sciences > Ben-Gurion University of the Negev > Beer-Sheva 84105 > Israel > Phone: 972-8-647-2220 ; Fax: 646-1710 > Skype: boaz.shaanan > > ‎

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Re: [phenixbb] Twinning Refinement
by Eric Larson 28 Mar '10

28 Mar '10

Dear Joe, It is not uncommon for proteins to crystallize in different crystal forms when in complex with different substrates or inhibitors. Trust that the absurdly high R factors (38% in the lowest resolution shell!?!?) despite the great lengths you went through with error models, etc. and the fact that scalepack is trying to throw out 20% of your data is a hint that you may be in the wrong spacegroup. Also, most of your "systematic absences" have an I/sig >2.5 and so probably are not absent. Were the predictions falling on spots during integration? This may provide another clue. I think you need to go back to HKL and reprocess pretending that you don't know that the crystals are "well characterized". You may have a new crystal form. good luck, Eric __________________________ Eric Larson, PhD MSGPP Consortium Department of Biochemistry Box 357742 University of Washington Seattle, WA 98195 > Date: Fri, 26 Mar 2010 05:13:07 +0000 > From: Joseph Brock <joeylives2ride(a)hotmail.com> > To: <phenixbb(a)phenix-online.org> > Subject: [phenixbb] Twinning Refinement > Message-ID: <SNT120-W557FCF7E111C0FEA167769B230(a)phx.gbl> > Content-Type: text/plain; charset="iso-8859-1" > > Dear Phenix Users, > > I'm currently using version: > Version: 1.4 > Release tag: 3 > cctbx tag: 2008_12_07_1353 > Platform: mac-intel-osx osx-10.5.6 > > I am working on characterising substrate/inhibitor interactions of a protein, the structure has been solved many times so its unit cell dimensions, contents (1 molecule per ASU) and space group (P3121) are well characterized. > > However, I have recently encountered several crystals that appear exhibit merohedral twinning, and am having trouble converging the R-factors to reasonable levels. The details of one such data set is described below: > > Diffraction to ~1.9A was recorded using a high and low resolution pass of 180? each. When processed with HKL2000 separately or together, Scalepack wanted to reject huge amounts of my data (~20%). I was forced to increase the error scale factor to 2 and adjust my error model to the very high R-factors of the low-resolution shells. The summary table from my final round of scalepack is: > Shell Lower Upper Average Average Norm. Linear Square > limit Angstrom I error stat. Chi**2 R-fac R-fac > 50.00 4.09 7648.3 1498.7 182.7 1.030 0.376 0.424 > 4.09 3.25 3885.1 568.9 64.1 1.410 0.416 0.480 > 3.25 2.84 1609.7 225.0 26.1 1.227 0.451 0.517 > 2.84 2.58 807.9 97.1 25.3 1.958 0.439 0.561 > 2.58 2.39 496.6 59.7 22.0 1.060 0.257 0.268 > 2.39 2.25 335.5 53.0 18.1 0.717 0.275 0.238 > 2.25 2.14 221.7 19.0 17.4 2.389 0.354 0.298 > 2.14 2.05 143.1 19.5 17.5 1.537 0.459 0.351 > 2.05 1.97 87.0 20.2 17.1 1.079 0.663 0.480 > 1.97 1.90 54.6 20.3 16.7 1.073 0.990 0.696 > All reflections 1588.3 269.2 41.9 1.350 0.400 0.444 > > In addition, many systematic absences appear to be present: > > Intensities of systematic absences > h k l Intensity Sigma I/Sigma > > 0 0 5 177.7 56.7 3.1 > 0 0 7 255.5 70.6 3.6 > 0 0 8 264.8 73.2 3.6 > 0 0 10 595.0 164.2 3.6 > 0 0 11 2343.5 1289.9 1.8 > 0 0 13 321.3 125.4 2.6 > 0 0 14 66.5 21.8 3.1 > 0 0 16 238.0 76.3 3.1 > 0 0 17 394.3 109.1 3.6 > 0 0 19 13.0 7.1 1.8 > 0 0 20 650.1 179.5 3.6 > 0 0 22 199.6 55.6 3.6 > 0 0 23 953.9 372.0 2.6 > 0 0 25 192.2 62.2 3.1 > 0 0 26 1038.7 405.0 2.6 > 0 0 28 96.3 28.9 3.3 > 0 0 29 2303.0 897.0 2.6 > 0 0 31 12.0 11.5 1.0 > 0 0 32 1622.4 516.5 3.1 > 0 0 34 11.5 13.8 0.8 > 0 0 35 22.8 14.8 1.5 > 0 0 37 27.9 18.0 1.5 > 0 0 38 154.3 45.6 3.4 > 0 0 40 55.8 27.8 2.0 > 0 0 41 35.5 23.7 1.5 > 0 0 43 -25.3 34.4 -0.7 > 0 0 44 67.7 32.1 2.1 > > > > The data has an overall completeness of 99.7%. > > When I run the data trough xtriage, it tells me: > > Statistics depending on twin laws > ----------------------------------------------------------------- > | Operator | type | R obs. | Britton alpha | H alpha | ML alpha | > ----------------------------------------------------------------- > | -h,-k,l | M | 0.307 | 0.301 | 0.256 | 0.022 | > ----------------------------------------------------------------- > > Patterson analyses > - Largest peak height : 5.288 > (corresponding p value : 0.86552) > > > The largest off-origin peak in the Patterson function is 5.29% of the > height of the origin peak. No significant pseudotranslation is detected. > > The results of the L-test indicate that the intensity statistics > are significantly different than is expected from good to reasonable, > untwinned data. > As there are twin laws possible given the crystal symmetry, twinning could > be the reason for the departure of the intensity statistics from normality. > It might be worthwhile carrying out refinement with a twin specific target function. > > I also estimated the twin fraction with the following server: > > http://nihserver.mbi.ucla.edu/Twinning/ > > And found it to about 20% (using data from 6-3A). > > After phasing the data with rigid body refinement in Refmac with intensity based twin refinement (brings both R-factors to ~36%), I have tried doing a twin refinement with Phenix: > > %phenix.refine model.pdb data.mtz twin_law="-h,-k,l" strategy=rigid_body+individual_sites+group_adp > > > The R_factors consistently diverge to the following values: > > Final R-work = 0.3392, R-free = 0.4360 > > Simulated annealing/TLS/ordered solvent/messing with wxc/wxu weights does not seem to improve the situation. I have also tried this with and without prior detwinning with the CCP4 program "Detwin", with similar results. > > Reindexing to -h,-k,l gives similar R-factors after rigid body refinement but after refinement with Phenix, things get even worse: > Final R-work = 0.3919, R-free = 0.5059 > > I was surprised to see that the fit to the map using both indexing conventions are comparable even though this should effectively reverse the hand of the structure. I assume this is because twin refinement is basically doing the job of "partial reindexing" on those parts of the lattice which are twinned? > > I have been working on this for about a week now and can't for the life of me find a way forward. If anyone can offer any suggestions It would greatly be appreciated. Im slowly beginning to lose my sanity.... > > BTW I don't think my problems stem from misindexing, although the beam was wondering all over the place during this block of data collection, I have previously solved another structure at the same d and xbeam ybeam values without any trouble. > > Sorry about the v.long post. Thought it would be better to give too much information rather than not enough =) > > Many thanks for all your suggestions in advance and for everything I > have learned from this community in the past. Cheers, > > Joe > PhD student. > > > > > > > > > > > > > > > > > > > > _________________________________________________________________ > Get personal with Windows. Download a free gift for your PC. > http://experience.windows.com >

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Re: [phenixbb] pointer distances
by Maia Cherney 26 Mar '10

26 Mar '10

Thank you, Paul. There is also difference in recording water. Should it be ATOM or HETATM? Phenix makes it HETATM, but coot makes it ATOM. Here is an example that was saved after adding one water molecule in coot (after refinement in phenix). HETATM10472 O HOH S1252 75.727 6.379 70.023 1.00 31.17 O HETATM10473 O HOH S1253 40.692 -0.062 54.840 1.00 37.64 O TER 10474 HOH S1253 ATOM 10475 O HOH S1254 75.842 2.043 56.024 1.00 35.64 O TER 10476 HOH S1254 END Maia Paul Emsley wrote: > Maia Cherney wrote: >> Hi Paul, >> >> Coot saves pdb files with TER card. The problem is the TER card takes >> the next atom number. >> >> >> ATOM 2303 C4 ADP A 288 33.070 4.240 14.161 1.00 >> 11.08 C TER 2304 ADP A 288 ATOM 2305 O >> SER B -1 >> >> The same model after phenix gives no number to the TER card. >> >> ATOM 2303 C4 ADP A 288 33.070 4.240 14.161 1.00 >> 11.08 C >> TER >> ATOM 2304 O SER B -1 >> >> >> As a result, the number of atoms in the pdb files is different. That >> is confusing. Could you please fix this problem. >> >> Maia >> >> > > > Hi Maia, > > It seems to us that this is an issue with Phenix, not Coot or mmdb. > > Have a look here: > > http://www.wwpdb.org/documentation/format32/sect9.html#TER > > "The serial number of the TER record is one number greater than the > serial number of the ATOM/HETATM preceding the TER" > > Regards, > Paul. > > > > >

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Twinning Refinement
by Joseph Brock 26 Mar '10

26 Mar '10

Dear Phenix Users, I'm currently using version: Version: 1.4 Release tag: 3 cctbx tag: 2008_12_07_1353 Platform: mac-intel-osx osx-10.5.6 I am working on characterising substrate/inhibitor interactions of a protein, the structure has been solved many times so its unit cell dimensions, contents (1 molecule per ASU) and space group (P3121) are well characterized. However, I have recently encountered several crystals that appear exhibit merohedral twinning, and am having trouble converging the R-factors to reasonable levels. The details of one such data set is described below: Diffraction to ~1.9A was recorded using a high and low resolution pass of 180º each. When processed with HKL2000 separately or together, Scalepack wanted to reject huge amounts of my data (~20%). I was forced to increase the error scale factor to 2 and adjust my error model to the very high R-factors of the low-resolution shells. The summary table from my final round of scalepack is: Shell Lower Upper Average Average Norm. Linear Square limit Angstrom I error stat. Chi**2 R-fac R-fac 50.00 4.09 7648.3 1498.7 182.7 1.030 0.376 0.424 4.09 3.25 3885.1 568.9 64.1 1.410 0.416 0.480 3.25 2.84 1609.7 225.0 26.1 1.227 0.451 0.517 2.84 2.58 807.9 97.1 25.3 1.958 0.439 0.561 2.58 2.39 496.6 59.7 22.0 1.060 0.257 0.268 2.39 2.25 335.5 53.0 18.1 0.717 0.275 0.238 2.25 2.14 221.7 19.0 17.4 2.389 0.354 0.298 2.14 2.05 143.1 19.5 17.5 1.537 0.459 0.351 2.05 1.97 87.0 20.2 17.1 1.079 0.663 0.480 1.97 1.90 54.6 20.3 16.7 1.073 0.990 0.696 All reflections 1588.3 269.2 41.9 1.350 0.400 0.444 In addition, many systematic absences appear to be present: Intensities of systematic absences h k l Intensity Sigma I/Sigma 0 0 5 177.7 56.7 3.1 0 0 7 255.5 70.6 3.6 0 0 8 264.8 73.2 3.6 0 0 10 595.0 164.2 3.6 0 0 11 2343.5 1289.9 1.8 0 0 13 321.3 125.4 2.6 0 0 14 66.5 21.8 3.1 0 0 16 238.0 76.3 3.1 0 0 17 394.3 109.1 3.6 0 0 19 13.0 7.1 1.8 0 0 20 650.1 179.5 3.6 0 0 22 199.6 55.6 3.6 0 0 23 953.9 372.0 2.6 0 0 25 192.2 62.2 3.1 0 0 26 1038.7 405.0 2.6 0 0 28 96.3 28.9 3.3 0 0 29 2303.0 897.0 2.6 0 0 31 12.0 11.5 1.0 0 0 32 1622.4 516.5 3.1 0 0 34 11.5 13.8 0.8 0 0 35 22.8 14.8 1.5 0 0 37 27.9 18.0 1.5 0 0 38 154.3 45.6 3.4 0 0 40 55.8 27.8 2.0 0 0 41 35.5 23.7 1.5 0 0 43 -25.3 34.4 -0.7 0 0 44 67.7 32.1 2.1 The data has an overall completeness of 99.7%. When I run the data trough xtriage, it tells me: Statistics depending on twin laws ----------------------------------------------------------------- | Operator | type | R obs. | Britton alpha | H alpha | ML alpha | ----------------------------------------------------------------- | -h,-k,l | M | 0.307 | 0.301 | 0.256 | 0.022 | ----------------------------------------------------------------- Patterson analyses - Largest peak height : 5.288 (corresponding p value : 0.86552) The largest off-origin peak in the Patterson function is 5.29% of the height of the origin peak. No significant pseudotranslation is detected. The results of the L-test indicate that the intensity statistics are significantly different than is expected from good to reasonable, untwinned data. As there are twin laws possible given the crystal symmetry, twinning could be the reason for the departure of the intensity statistics from normality. It might be worthwhile carrying out refinement with a twin specific target function. I also estimated the twin fraction with the following server: http://nihserver.mbi.ucla.edu/Twinning/ And found it to about 20% (using data from 6-3A). After phasing the data with rigid body refinement in Refmac with intensity based twin refinement (brings both R-factors to ~36%), I have tried doing a twin refinement with Phenix: %phenix.refine model.pdb data.mtz twin_law="-h,-k,l" strategy=rigid_body+individual_sites+group_adp The R_factors consistently diverge to the following values: Final R-work = 0.3392, R-free = 0.4360 Simulated annealing/TLS/ordered solvent/messing with wxc/wxu weights does not seem to improve the situation. I have also tried this with and without prior detwinning with the CCP4 program "Detwin", with similar results. Reindexing to -h,-k,l gives similar R-factors after rigid body refinement but after refinement with Phenix, things get even worse: Final R-work = 0.3919, R-free = 0.5059 I was surprised to see that the fit to the map using both indexing conventions are comparable even though this should effectively reverse the hand of the structure. I assume this is because twin refinement is basically doing the job of "partial reindexing" on those parts of the lattice which are twinned? I have been working on this for about a week now and can't for the life of me find a way forward. If anyone can offer any suggestions It would greatly be appreciated. Im slowly beginning to lose my sanity.... BTW I don't think my problems stem from misindexing, although the beam was wondering all over the place during this block of data collection, I have previously solved another structure at the same d and xbeam ybeam values without any trouble. Sorry about the v.long post. Thought it would be better to give too much information rather than not enough =) Many thanks for all your suggestions in advance and for everything I have learned from this community in the past. Cheers, Joe PhD student. _________________________________________________________________ Get personal with Windows. Download a free gift for your PC. http://experience.windows.com

4 4

project defaults ncs.params not read or overridden/overwritten by GUI?
by hari jayaram 25 Mar '10

25 Mar '10

Hi I am quite sure I am doing something wrong , but the refinement seems to always re-determine the NCS definitions despite it being set in the ncs.params file in the project defaults directory. Here is what I did: 1. I set the NCS groups definition in the GUI to go from residues 35:445 , 2. I check that using the view pick . Everything looks fine 3. I click the Green update and exit button 4. I look at the ncs.params file in the project defaults directory and it indeed reflects the changes . 5. I start the refinement from the GUI and the ncs section seems to have been reset to 26:450 . I even tried adding the ncs.params file to the Input files section, but to no avail. The ncs seems to always get re-determined and I end up getting an excessive distance stoppage of refinement. I even made sure I dont have the Find NCS restraints automatically button checked. Any idea why I cannot get the gui run refinement to remember my ncs definitions. Thanks in advance Hari

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FreeR label?
by J. Fleming 25 Mar '10

25 Mar '10

Hello all, I used AutoSol to generate a model from my Se-Met crystal. I then used this output model, overall_best.pdb, for AutoBuild1 in which I extended the data to include a set of native data. At this point I took the exptl_fobs_phases_freeR_flags.mtz output and used it with a different model that I believe to be accurate to carry out AutoBuild2. The problem I'm having is that I can't run Refmac/Phenix refinements on the output from AutoBuild2: overall_best.pdb and overall_best_denmod_map_coeffs.mtz. Both pieces of software say the FreeR labels are missing although in the AutoBuild2 output PDB there is a FreeR test set count of ~2,000. When I list all labels in Refmac I see: F FP P PHIM W FOMM Using these labels doesn't work for refinement. I used default settings for AutoSol/AutoBuild except for the number of Se-Met sites and of course the f' and f'' etc. I'm assuming the problem is with the MTZ but I'm not sure where to troubleshoot. Does anyone have any thoughts? Thanks in advance, Jon

2 1

OS X PowerPC builds
by Ben Eisenbraun 24 Mar '10

24 Mar '10

Hi PHENIXians, I'm updating our nightly build, and I noticed that there are no current builds for OS X PowerPC. Are the PowerPC builds going to be discontinued? I searched the mailing list, but I didn't see an announcement. Thanks. -ben -- | Ben Eisenbraun | Software Sysadmin | | Structural Biology Grid | http://sbgrid.org | | Harvard Medical School | http://hms.harvard.edu |

3 2

Bulk solvent scaling & unstructured protein
by Mads Beich-Frandsen 24 Mar '10

24 Mar '10

Hi all, I have a P1-crystal and data (quite anisotropic to 2.85Å, 90% complete) of a partly unstructured protein, of which some 35% of the sequence is intrinsically unstructured. The structure has been solved by molecular replacement, and it has been refined to Rw/Rf 20/26 with Phenix. As expected, not much of the predicted unstructured region show clear density. The oligomeric protein packs in layers facing oneanother, leaving the unstructured parts 'packing' towards eachother, in what appears as huge solvent-channels. My question is now: Is there an approach to optimizing bulk solvent scaling in Phenix, keeping with the thought, that 30-35% of my protein sequence should be present where Phenix assigns bulk solvent. Thank you! -And any other tricks and tips will much appreciated! Rgds., Mads ------------------------------ Mads Beich-Frandsen Department of Structural and Computational Biology Max F. Perutz Laboratories University of Vienna Campus Vienna Biocenter 5 A-1030 Vienna Austria E-mail: mads.beich-frandsen(a)univie.ac.at Phone: +43-1-4277-52225 Fax: +43-1-4277-9522 Web: http://www.mfpl.ac.at/index.php?cid=58

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where to find phenix.phaser 2.2.3 documentation on keywords
by Bjørn Panyella Pedersen 24 Mar '10

24 Mar '10

Dear list I am struggling to find the documentation for Phaser 2.2.3 (as part of phenix.phaser v1.6.289), and more specifically the list of allowed keywords and what their significance is. In my hands the PACK keyword is no longer allowed in v2.2.3 (works fine in v2.1.4) while two alternatives: SELECT CUTOFF DISTANCE and QUICK are suggested instead. However I cannot find any details on what these do. Ultimately I want to allow packing clashes beyond the default of 10. A google-search only give me hits on the Phaser homepage with documentation for v.2.1 (http://www-structmed.cimr.cam.ac.uk/phaser/documentation/index.html), and the phenix.phaser documentation (http://www.phenix-online.org/documentation/phaser.htm) does not include a keyword-list. Hope somebody can help with this simple problem. Best Bjørn -- Bjørn Panyella Pedersen, PhD Postdoc PUMPKIN, Centre for Membrane Pumps in Cells and Disease University of Aarhus, Dept. Molecular Biology Gustav Wieds Vej 10C DK-8000 Aarhus C, Denmark Phone: +45 89425261 E-mail: bjopp(a)bioxray.au.dk http://www.bioxray.au.dk

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