December 2010 - phenixbb - phenix-online.org

scattering factors
by Goragot Wisedchaisri 21 Jun '11

21 Jun '11

Hi, I am new to Phenix but I have used Solve/Resolve in the past. I am currently using Phenix 1.6.2 and I have electron diffraction data to ~2A from a 300kV electron microscope that I would like to use Autobuild and phenix.refine to iteratively rebuild and refine my partial structure. I have a file containing electron scattering factors for 300kV EM that has been used successfully for refinement with CNS before for electron diffraction data. How can I tell Phenix to use electron scattering factors during refinement? I think currently Phenix has 4 choices for X-ray and neutron scattering factors but not for electron scattering. Is there a good way to implement electron scattering factors into phenix library? Any suggestions are welcome. George Wisedchaisri

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Geometry problem with sugars refined in phenix
by Tirumala Kumar Chowdary 03 Mar '11

03 Mar '11

Hi, I have refined a structure with NAGs linked to ASNs at 3 places in my structure. I used the right link definitions and the NAG definitions are from Phenix library. Phenix refined all the sugars right and made the right links between the NAGs. However, while submitting, PDB found problem with the geometry of NAGs linked to the ASN at two places. This is the issue -the atoms around C1 atom of the sugar molecule NAG A #810 and NAG A #1670 are on a plane and the C1 atom center is far off to be tetrahedral. Please, verify the chirality of C1 and provide the correct coordinates if necessary.- Any ideas on how to fix the geometry of these sugars will be of great help. Regularization and real space refine in Coot is not working or I don't know how to do it. I am looking for alternative ways to fix this problem. Thank You Tirumal

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Problem with Autobuild
by Claudia Scotti 12 Jan '11

12 Jan '11

Dear List, Sorry fo r the easy question, but I have a problem with Autobuild. I'm trying to rebuild a scFv, composed of two domains linked by a linker. I've managed to find an MR solution with a polyalanine model deprived of the loops, which is my starting model for rebuilding. I've given Autobuild three input files: the mtz, the model coordinates and the sequence of the scFv, asking to model only the beta strands and helices. Problem is that in the final model Autobuild seems to guess incorrectly the density of two beta-strands, inserting the linker there instead of the expected side chains. Any suggestions on how to correct this? Shall I manually rebuild this part to avoid problems? Or is it crucial to prevent errors, for example, that the model and the sequence are numbered so that they are in register? Thanks in advance, Claudia Claudia Scotti Dipartimento di Medicina Sperimentale Sezione di Patologia Generale Universita' di Pavia Piazza Botta, 10 27100 Pavia Italia Tel. 0039 0382 986335/8/1 Facs 0039 0382 303673 _________________________________________________________________ Hotmail: Trusted email with powerful SPAM protection. https://signup.live.com/signup.aspx?id=60969

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Questions about phenix.refine with twin_law
by Keitaro Yamashita 06 Jan '11

06 Jan '11

Dear Phenix developers, I'm working with pseudo-merohedrally twinned data (fraction 45%), using Phenix-dev-616. I have three questions about phenix.refine with twin_law. (running on the command line) During refinement with twin_law, the log file says x-ray target function is set to "twin_lsq_f". Does it mean, we cannot use maximum likelihood target for twinned data? If so, is it recommended to refine without twin_law at first several cycles? When I tried to refine using the model refined without twin_law, the target function was still ml, not twin_lsq_f although I specified twin_law. Is this a bug? When I used twin_law option, in the table "R-free likelihood based estimates", "Scale factor" were None in all resolution bins. Cannot scale factor be calculated during twin refinement? Thanks in advance and Wishing you the best holidays, Keitaro

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errors when disabling Rfree
by chene＠umbi.umd.edu 03 Jan '11

03 Jan '11

Dear Phenixers, I have a low resolution twinned data, for which I disabled cross validation in refinement. The refinement worked and exported the refined coordinates. However, the phs files for maps are empty and there were such errors as below. It seems the free set is required for maps. I wonder how to fix this problem? Thanks Chen Traceback (most recent call last): File "/home/chene/phenix-1.6.4-486/phenix/phenix/command_line/refine.py", line 11, in <module> command_line.run(command_name="phenix.refine", args=sys.argv[1:]) File "/home/chene/phenix-1.6.4-486/phenix/phenix/refinement/command_line.py", line 103, in run map_manger.write_files() File "/home/chene/phenix-1.6.4-486/phenix/phenix/refinement/driver.py", line 1281, in write_files fmodel = self.refine_object.fmodels.fmodel_xray(), params = mtz_mc) File "/home/chene/phenix-1.6.4-486/cctbx_project/mmtbx/maps/__init__.py", line 290, in map_coefficients_from_fmodel centrics_pre_scale = params.centrics_pre_scale) File "/home/chene/phenix-1.6.4-486/cctbx_project/mmtbx/twinning/twin_f_model.py", line 1780, in map_coefficients w2 = w2) File "/home/chene/phenix-1.6.4-486/cctbx_project/mmtbx/twinning/twin_f_model.py", line 1695, in map_coefficients sigmaa_object = self.sigmaa_object( detwinned_data=dt_f_obs,f_model_data=tmp_f_model, tmp_free=tmp_free,forced_update=True) File "/home/chene/phenix-1.6.4-486/cctbx_project/mmtbx/twinning/twin_f_model.py", line 1504, in sigmaa_object kernel_width_free_reflections=200, File "/home/chene/phenix-1.6.4-486/cctbx_project/mmtbx/scaling/sigmaa_estimation.py", line 131, in __init__ raise RuntimeError("No free reflections.") RuntimeError: No free reflections. Chen Chen, PhD, Research Associate Center for Advanced Research in Biotechnology (CARB), University of Maryland Biotechnology Institute (UMBI), 9600 Gudelsky Drive, Rockville, MD 20850 240-314-6122

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Automated Mg & K ions picking
by Hasan Demirci 02 Jan '11

02 Jan '11

Hi, I have a low resolution data and I am trying to place Mg++ and K+ ions. As far as I know for ligand search at least 3 atoms required. Is it possible to do an automated search of these single atom ions by using phenix similar to automated water picking protocol? Thanks. -- Hasan DeMirci, Ph.D. Postdoctoral Fellow Department of Molecular Biology, Cellular Biology & Biochemistry Brown University 185 Meeting Street Providence, RI 02912 (401) 863-3652 lab (SFH) (401) 863-6124 lab (ship st) (401) 226-7852 cell Hasan_DeMirci(a)Brown.edu demircha99(a)gmail.com

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MACOSX_DEPLOYMENT_TARGET mismatch between PHENIX and Coot
by Ben Eisenbraun 30 Dec '10

30 Dec '10

Howdy PHENIXians, One of my users reported this error: File "/programs/i386-mac/coot/coot-latest/lib/python2.7/sysconfig.py", line 300, in _init_posix raise IOError(msg) IOError: $MACOSX_DEPLOYMENT_TARGET mismatch: now "10.4" but "10.5" during configure The person is running on OS X Intel, using a PHENIX nightly and trying to call Coot. It looks like the PHENIX nightlies are built with MACOSX_DEPLOYMENT_TARGET=10.4, and the Coot I built used M_D_T=10.5 and Python is unhappy about this. It's easy to test this: $ export MACOSX_DEPLOYMENT_TARGET=10.3 $ phenix.python Traceback (most recent call last): File "/programs/i386-mac/phenix/dev-606/phenix-dev-606/build/mac-intel-osx/base/Python.framework/Versions/Current/lib/python2.7/site.py", line 553, in <module> <snip> IOError: $MACOSX_DEPLOYMENT_TARGET mismatch: now "10.3" but "10.4" during configure Or if you have access to one of our installations: $ phenix.python import os os.system('coot') Results in the original error pasted above. After playing a bit, I came up with a workaround. If you just set the M_D_T to 10.5 before starting Coot and _after_ starting PHENIX, it all seems to work. E.g. I can start Coot using this script: $ cat coot.py #!/usr/bin/env phenix.python import os os.putenv('MACOSX_DEPLOYMENT_TARGET', '10.5') os.system('coot') And since the 'coot' binary in the PATH is a wrapper script, I can just set it in the environment there. My question is: does Python actually need this? Is my workaround going to break something? I'm not enough of a Pythonista to be able to tell from looking at the sysconfig code if this will be an issue. There is a comment in the source: # On MacOSX we need to check the setting of the environment variable # MACOSX_DEPLOYMENT_TARGET: configure bases some choices on it so # it needs to be compatible. But it's not clear to me when it's going to be used. I'm almost certainly going to implement the workaround, so I'm mostly posting this for the list archives and to see if anyone has a better idea. Thanks. -ben -- | Ben Eisenbraun | SBGrid Consortium | http://sbgrid.org | | Harvard Medical School | http://hms.harvard.edu |

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LigandFit (distorted manesium hexahydrate cluster)
by Hasan Demirci 28 Dec '10

28 Dec '10

Dear All, I am trying to run " LigandFit " with the following hydrated magnesium hexahydrate cluster (without the hydrogens) pdb. "HETATM 7 MG MG6 A 1 -53.936 117.342 91.273 1.00128.70 A MG HETATM 2 O1 MG6 A 1 -55.351 117.224 89.749 1.00128.62 A O HETATM 3 O2 MG6 A 1 -52.532 117.421 92.718 1.00127.25 A O HETATM 4 O3 MG6 A 1 -55.370 118.284 92.428 1.00127.74 A O HETATM 5 O4 MG6 A 1 -53.253 119.219 90.518 1.00128.43 A O HETATM 6 O5 MG6 A 1 -54.385 115.379 91.937 1.00127.84 A O HETATM 7 O6 MG6 A 1 -52.566 116.391 89.994 1.00128.62 A O " LigandFit automatically runs the elbow and creates a new search pdb file with hydroges and while doing this, elbow totally screws up the original starting geometry of the Oxygen atoms within the cluster after the addition of hydrogens. "HETATM 1 MG MG6 A 1 -53.913 117.323 91.231 1.00128.70 A MG HETATM 2 O1 MG6 A 1 -55.140 117.947 90.141 1.00128.62 A O HETATM 3 O2 MG6 A 1 -53.080 118.061 92.589 1.00127.25 A O HETATM 4 O3 MG6 A 1 -55.453 117.480 92.061 1.00127.74 A O HETATM 5 O4 MG6 A 1 -52.768 118.528 90.669 1.00128.43 A O HETATM 6 O5 MG6 A 1 -53.676 115.727 91.923 1.00127.84 A O HETATM 7 O6 MG6 A 1 -53.363 116.194 90.004 1.00128.62 A O HETATM 8 H11 MG6 A 1 -55.461 117.161 89.473 1.00128.62 A H HETATM 9 H21 MG6 A 1 -52.333 117.378 92.967 1.00127.25 A H HETATM 10 H31 MG6 A 1 -55.430 118.350 92.700 1.00127.74 A H HETATM 11 H41 MG6 A 1 -53.300 119.422 90.378 1.00128.43 A H HETATM 12 H51 MG6 A 1 -54.636 115.255 92.077 1.00127.84 A H HETATM 13 H61 MG6 A 1 -52.319 116.372 89.793 1.00128.62 A H " Is it a bug or am I making something wrong? Does the search pdb HAVE TO be covalently linked? or can I search for a cluster? Thanks. -- Hasan DeMirci

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ramachandran_restraints
by José Trincão 28 Dec '10

28 Dec '10

Dear all, I am refining a structure to 2.9 A, with pretty bad experimental data (P1, ~5400 residues in the A.U. (4 mol), anisotropic, fairly incomplete...). I have been running phenix.refine with NCS, 1 ADP per residue, lower target weights, TLS. My R/Rfree are stuck at about 2.4/3.05. I was getting around 2% ramachandran outliers at every cycle so I have been giving the nightly builds a shot. Now I get 0.2% outliers without changing any parameters for the ramachandra_restraints but it is forcing some of the peptide bonds out of the density. What can I tweak to improve the refinement? Thanks all in advance! Jose José Trincão, PhD CQFB@FCT-UNL 2829-516 Caparica, Portugal "It's very hard to make predictions... especially about the future" - Niels Bohr

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Re: [phenixbb] Simple Phaser Question (Ed Pozharski
by Joseph Noel 27 Dec '10

27 Dec '10

Hi Ed, Yes, that is what I generally do but it sometimes is a slightly different so I wanted a more general approach. Joe ___________________________________________________________ Joseph P. Noel, Ph.D. Investigator, Howard Hughes Medical Institute Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics The Salk Institute for Biological Studies 10010 North Torrey Pines Road La Jolla, CA 92037 USA Phone: (858) 453-4100 extension 1442 Cell: (858) 349-4700 Fax: (858) 597-0855 E-mail: noel(a)salk.edu Web Site (Salk): http://www.salk.edu/faculty/faculty_details.php?id=37 Web Site (HHMI): http://hhmi.org/research/investigators/noel.html ___________________________________________________________ On Dec 25, 2010, at 12:00 PM, phenixbb-request(a)phenix-online.org wrote: > Send phenixbb mailing list submissions to > phenixbb(a)phenix-online.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://phenix-online.org/mailman/listinfo/phenixbb > or, via email, send a message with subject or body 'help' to > phenixbb-request(a)phenix-online.org > > You can reach the person managing the list at > phenixbb-owner(a)phenix-online.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of phenixbb digest..." > > > Today's Topics: > > 1. Simple Phaser Question (Joseph Noel) > 2. Re: Simple Phaser Question (Ed Pozharski) > 3. Questions about phenix.refine with twin_law (Keitaro Yamashita) > 4. Re: Questions about phenix.refine with twin_law (Peter Zwart) > 5. Re: Questions about phenix.refine with twin_law (Pavel Afonine) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Fri, 24 Dec 2010 17:11:37 -0800 > From: Joseph Noel <noel(a)salk.edu> > To: phenixbb(a)phenix-online.org > Subject: [phenixbb] Simple Phaser Question > Message-ID: <5E3B81ED-4C13-488E-8C28-33DB29263AEF(a)salk.edu> > Content-Type: text/plain; charset="us-ascii" > > Hi All, > > I am working with a protein that is a physiological dimer. On occasion I obtain a unit cell with one monomer in the asymmetric unit but most often I obtain an enantiomorphic space group with an expanded C axis that contains two molecules in the asymmetric unit. Anyway, that is all moot to some extent. I am wondering if for the case of my NCS dimer, is there a way using Phaser in Phenix to ensure that when both monomers are found, they are "close together" representative of the physiological dimer? When I search with individual monomers I often obtain a solution with two monomers but in different asymmetric units. Of course, I could easily do the transformation to form the physiological NCS dimer for later refinement but just wondering if I could avoid this from the get go with the appropriate Phaser keyword input (GUI if possible). > > Thanks and Happy Holidays! > > Joe > ___________________________________________________________ > Joseph P. Noel, Ph.D. > Investigator, Howard Hughes Medical Institute > Professor, The Jack H. Skirball Center for Chemical Biology and Proteomics > The Salk Institute for Biological Studies > 10010 North Torrey Pines Road > La Jolla, CA 92037 USA > > Phone: (858) 453-4100 extension 1442 > Cell: (858) 349-4700 > Fax: (858) 597-0855 > E-mail: noel(a)salk.edu > > Web Site (Salk): http://www.salk.edu/faculty/faculty_details.php?id=37 > Web Site (HHMI): http://hhmi.org/research/investigators/noel.html > ___________________________________________________________ > >

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