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NCS and R-Values Hung up at 0.42/0.46 for 2.1Å resolution
by John Bruning 11 Jul '15

11 Jul '15

I collected two datasets of the same ligand bound structure at 2.4 and 2.1 Å resolution. The apo structure has already been solved to 2.2Å resolution in P31 (and P3121 for SeMet). After processing each dataset as both P31 and P3121 in MOSFLM, I proceeded with MR with Phaser using sequential partial search models to place either 3 copies in the ASU for P3121, or 6 copies for P31. (The previously solved apo structure had 6 copies of the same protein in the ASU). *** in summary two datasets, processed as both P31 or P3121 After running xtriage for either .mtz, I get this warning about NCS: Distance to origin : 56.728 Height relative to origin : 26.388 % Translational pseudo-symmetry is very likely present in these data. Be aware that this will change the intensity statistics and may impact subsequent analyses, and in practice may lead to higher R-factors in refinement. Regardless, I can proceed with the MR using sequential partial search models to place either 3 copies (P3121) or 6 copies (P31) with decent solutions (i.e. packing looks good upon inspection, scoring looks appropriate -> SOLU SET RFZ=2.8 TFZ=8.3 PAK=13*LLG*=-37 *LLG*=2199 as an example). However, I did get the following somewhat expected warnings: Number of known components (1) not divisible by 2: Translational *NCS* correction not applied Large non-origin Patterson peak indicates that translational *NCS* is present Upon any attempt at initial refinement (with a number of different strategies), the R-factors are hung up > 0.42 (for example in the P3121, 2.1Å case): Start R-work = 0.4966, R-free = 0.5133; Final R-work = 0.4231, R-free = 0.4477 My concern is that there is some pathology that is not being recognized (merohedral twinning) or that the NCS/pseudosymmetry is not being addressed appropriately. -- Cheers, John

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Re: [phenixbb] Fwd: [ccp4bb] Phenix; converting a map to structure factors
by Pavel Afonine 11 Jul '15

11 Jul '15

Hi Mark, Tom copied me your email. > As I'm sure you are aware there is tremendous interest in building > into and refining against low resolution (by X-ray standards) EM maps. > Could you comment to the phenix BB about whether its appropriate to > convert maps to reciprocal space and use ML refinement? While it is a possible way of doing this (and this is how it's been done in the past) I don't think it is a good route to follow. In case of cryo-EM your data is map, so why not just refine against the map? Why take a detour through reciprocal-space by converting map into structure factors (=manipulating your original data) and doing reciprocal space using refinement programs that were designed for crystallography? With this in mind we have developed a new refinement tool in Phenix (it is still in active development!) called phenix.real_space_refine that is designed to refine atomic models directly into maps (any map: X-ray, neutron, cryo-EM, low or high resolution), for quick summary see http://phenix-online.org/presentations/real_space_refine.pdf as well as documentation page (at the bottom): http://phenix-online.org/documentation/ and newsletter article (page 43): http://phenix-online.org/newsletter/CCN_2013_07.pdf Let me know if you have any questions or comments! Pavel

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atom vdW dictionary for Python
by David Shin 11 Jul '15

11 Jul '15

Hi - I'm writing a Python script to measure the volume of pockets within protein structures - plus extra bells and whistles... thus a custom job. I was wondering just for speed, if someone could point me to values for van der Waals radii that are somewhat agreed upon for protein atoms, or if there is some dictionary already made that someone could point to that resides in phenix or some other structural biology package that would be ok for me to copy/use. Thanks, Dave

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Re: [phenixbb] [ccp4bb] Phenix; converting a map to structure factors
by Terwilliger, Thomas Charles 11 Jul '15

11 Jul '15

Hi Reza, Just use: phenix.map_to_structure_factors map.ccp4 d_min=2.5 or something like that, All the best, Tom T On Jul 10, 2015, at 11:27 AM, Reza Khayat wrote: Hi, Is it possible to convert a map to structure factors using Phenix? Thanks. Best wishes, Reza Reza Khayat, PhD Assistant Professor City College of New York Department of Chemistry New York, NY 10031

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NCS and R-Values Hung up at ~0.42/0.46
by John Bruning 10 Jul '15

10 Jul '15

Hi Everyone, I collected two datasets of the same ligand bound structure at 2.4 and 2.1 Å resolution. The apo structure has already been solved to 2.2Å resolution in P31 (and P3121 for SeMet). After processing each dataset as both P31 and P3121 in MOSFLM, I proceeded with MR with Phaser using sequential partial search models to place either 3 copies in the ASU for P3121, or 6 copies for P31. (The previously solved apo structure had 6 copies of the same protein in the ASU). *** in summary two datasets, processed as both P31 or P3121 After running xtraige for either .mtz, I get this warning about NCS: Largest Patterson peak with length larger than 15 Angstrom: Frac. coord. : 0.333 -0.333 -0.153 Distance to origin : 56.728 Height relative to origin : 26.388 % p_value(height) : 2.659e-03symmetry. Translational pseudo-symmetry is very likely present in these data. Be aware that this will change the intensity statistics and may impact subsequent analyses, and in practice may lead to higher R-factors in refinement. Regardless, I can proceed with the MR using sequential partial search models to place either 3 copies (P3121) or 6 copies (P31) with decent solutions (i.e. packing looks good upon inspection, scoring looks appropriate -> SOLU SET RFZ=2.8 TFZ=8.3 PAK=13*LLG*=-37 *LLG*=2199 as an example). However, I did get the following somewhat expected warnings: Number of known components (1) not divisible by 2: Translational *NCS* correction not applied Large non-origin Patterson peak indicates that translational *NCS* is present Upon any attempt at initial refinement (with a number of different strategies), the R-factors are hung up > 0.42 (for example in the P3121, 2.1Å case): Start R-work = 0.4966, R-free = 0.5133 Final R-work = 0.4231, R-free = 0.4477 *** best R-factors from ~ 15 different strategies My concern is that there is some pathology that is not being recognized (merohedral twinning) or that the NCS/pseudosymmetry is not being addressed appropriately. Any suggestions in troubleshooting this would be much appreciated, as I have pretty much exhausted everything I could think of. -- Cheers, John

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(no subject)
by Ashok Nayak 10 Jul '15

10 Jul '15

Dear Phenixites, I have a helical bundle structure, where in I wish to understand by what rotation and about which axis the dimers are inter-related. What I get from the superposition with Superpose is the transformation matrix and not the axis, and the angles are also elusive. Ashok Nayak CSIR-CDRI Lucknow, India --

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Axis of Rotation
by Ashok Nayak 10 Jul '15

10 Jul '15

Dear Phenixites, I have a helical bundle structure, where in I wish to understand by what rotation and about which axis the dimers are inter-related. What I get from the superposition with Superpose is the transformation matrix and not the axis, and the angles are also elusive. Thanks in advance -- Ashok Senior Research Fellow - Dr JV Pratap, Lab No-LSN 008 Molecular and Structural Biology Division Central Drug Research Institute, Janakipuram Extension Lucknow-226031 India

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rosetta.build_phenix_interface problem
by Appu kumar 09 Jul '15

09 Jul '15

Dear All, I have installed Rosetta on Linux machine. When i am issuing the command " rosetta.build_phenix_interface" it is giving me following error scons: Building targets ... scons: *** [build/src/release/linux/2.6/64/x86/gcc/4.4/python/libObjexxFCL.so] Implicit dependency `/usr/local/lib/libdl.so' not found, needed by target `build/src/release/linux/2.6/64/x86/gcc/4.4/python/libObjexxFCL.so'. scons: building terminated because of errors. Would you please give me your valuable suggestions to successfully carry out the Rosetta refinement. Thank you Appu

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Rosetta Refinement problem
by Appu kumar 09 Jul '15

09 Jul '15

Dear All, I have installed Rosetta successfully on Linux machine and after installation it say building done. While refining a structure with "phenix.rosetta_refine" it is giving following problem End of input processing Sorry: The RosettaScripts executable could not be located. Please add the appropriate directory to your PATH environment variable, or set the variable ROSETTA_BIN to point to it. In my .cshrc file i have setup the path as follow setenv PHENIX_ROSETTA_PATH /home/appu/2014_09_29_NSLS_X29/rosetta_bin_linux_2015.25.57927_bundle setenv ROSETTA_BIN /home/appu/2014_09_29_NSLS_X29/rosetta_bin_linux_2015.25.57927_bundle/main/source/bin setenv phenix /home/appu/software/phenix/phenix-1.9-1692 setenv ROSETTA3_DB /home/appu/2014_09_29_NSLS_X29/rosetta_bin_linux_2015.25.57927_bundle/main/database I would appreciate any help and suggestions in executing the Rosetta refinement Thank you Appu

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Problem with python while running Autobuild
by Tam＠em.uni-frankfurt.de 09 Jul '15

09 Jul '15

Dear all, I am currently facing a problem of python while running the Autobuild in Phenix. phenix.autobuild data=data1.mtz model=model.pdb seq_file=protein.dat rebuild_in_place=False \ composite_omit_type=iterative_build_omit then it stopped with error Error in `/home/mauricetam/software/phenix-1.9-1692/build/intel-linux-2.6-x86_64/base/bin/python2.7': free(): invalid next size (normal): 0x0000000003e100a0 *** I wonder what's wrong with it. Regards Heng-Keat

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