- phenixbb - phenix-online.org

random half data sets
by Michael Thompson 13 Aug '14

13 Aug '14

Hello All, I'm interested in doing some comparisons of random half data sets, inspired by statistics like CC1/2, CC*, etc. Does phenix contain some tool to split unmerged data into 2 random sets? Thought I would ask before trying to write my own script. Thanks, Mike -- Michael C. Thompson Postdoctoral Scholar Institute of Genomics and Proteomics University of California, Los Angeles miket(a)chem.ucla.edu

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Alternate sequence
by Mullins, Elwood A. 13 Aug '14

13 Aug '14

Hello all, I'm having trouble refining a protein-DNA complex in which one of the DNA strands has a mixture of two different nucleotides at one position. Both are non-standard and require CIF files. I tried assigning each nucleotide the same chain identifier and the same residue number but unique alternate location identifiers. This didn't work. Phenix refined the model but only linked one of the nucleotides with the rest of the chain, pushing the 3' OH and 5' phosphate out of the density for the other nucleotide. Coot won't even open the model output by Phenix. I assume there's some way to do this. Thanks in advance, Elwood Elwood A. Mullins, Ph.D. <> elwood.mullins(a)vanderbilt.edu<mailto:[email protected]> <> tel 615.936.5234 <> fax 615.343.6707

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Calculate F (model)
by PC 13 Aug '14

13 Aug '14

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Re: [phenixbb] pdb_redo
by Nathaniel Echols 12 Aug '14

12 Aug '14

> > From: "Lenin Domínguez" <acheron24(a)gmail.com> > Subject: Re: [phenixbb] pdb_redo > I was wondering about PDB_REDO too. Your command line is priceless, Nat. > > I have one further question: Using phenix.fetch_pdb --maps shouldn't I be > able tro reproduce a figure from a paper showing the electron density of a > ligand? > Well, yes, usually. But: http://www.ncbi.nlm.nih.gov/pubmed/23385452 The one caveat is that there are a few legitimate manipulations that could make the figure look slightly different from how it appears in e.g. Coot: 1. Use of a finer FFT grid (d_min/5 or smaller, versus d_min/4 or d_min/3 which are the defaults for Phenix and Coot respectively) 2. Maximum entropy treatment (removes Fourier artifacts, extends coefficients to high resolution without actually adding information) 3. Map sharpening (2) and (3) should really be explicitly mentioned, however. And I have yet to see a case where these would make the difference between a ligand being detectable or not by eye. (Maximum entropy can sometimes improve the performance of LigandFit but the density is still pretty obvious to a human.) The maps from PDB_REDO shouldn't be hugely different from the maps that come out of phenix.maps, so looking at those results would be another control. I have tried using phenix.fetch_pdb, PDB_REDO (conservative and aggresive > refinement) as well as the data straight from EDS. > > Any thoughts? > Send me the PDB ID (and ligand name) off-list and I'll take a look. -Nat

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Re: [phenixbb] pdb_redo
by Ed Pozharski 12 Aug '14

12 Aug '14

I believe the intent is to provide electron density maps at the end of pdb_redo re-refinement process. Recent versions of coot allow direct download of pdb_redo maps and there are also pymol plugins. You could ask Robbie Joosten directly whether your specific intended use of pdb_redo output is kosher. Sent on a Sprint Samsung Galaxy S® III <div>-------- Original message --------</div><div>From: Nathaniel Echols <nechols(a)lbl.gov> </div><div>Date:08/11/2014 11:06 AM (GMT-05:00) </div><div>To: PC <patrick.cossins(a)inbox.com> </div><div>Cc: PHENIX user mailing list <phenixbb(a)phenix-online.org> </div><div>Subject: Re: [phenixbb] pdb_redo </div><div> </div>On Mon, Aug 11, 2014 at 10:50 AM, PC <patrick.cossins(a)inbox.com> wrote: I was wondering what the community thought of the use of PDB_REDO for MTZ files? I see that they have easy to download MTZ files but has anyone actively used them? Unless we're looking at something different, these are output from Refmac, and do not include all of the data contained in the original deposition. I am not sure if the data will have undergone other changes as well. For instance, the deposited structure factors for PDB ID 2whz include both the fully processed anomalous differences (DANO) and the anomalous intensities (I+/I- and sigmas). The MTZ file I found on PDB_REDO has neither, just FP with Friedel mates merged. This throws out important information. Personally, I just do this: phenix.fetch_pdb --mtz 2whz or this: phenix.fetch_pdb --maps 2whz (Perhaps someday we'll have a server for this.) I should mention however that this will fail on a significant fraction of PDB entries that do not adhere to the CIF standard, at least as implemented in CCTBX. -Nat

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pdb_redo
by PC 11 Aug '14

11 Aug '14

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Two ions at same position
by Eric Girard 09 Aug '14

09 Aug '14

Dear phenixbb members, I am refining a structure that contains Ca2+ atoms. The structure was determined in presence of lanthanide ions. Thus, the resulting density clearly indicates that a part of each Ca2+ sites is substituted with Eu3+ (let's say 75% Ca2+ and 25% Eu3+ per sites). How can I deal with such situation? Indeed phenix.refine complains when I try to put a Ca2+ ion and a Eu3+ one with the same coordinates (and with the occupancies mentionned above) and stop. Thanks for your help. Eric. -- **************************************************************** Eric Girard Extremophiles and Large Macromolecular Assemblies (ELMA) group Institut de Biologie Structurale UMR 5075 CEA-CNRS-UJF-PSB 71 avenue des Martyrs CS 10090 38044 Grenoble Cedex 9 Phone: +33 (0)4 57 42 86 45 Fax: +33 (0)4 76 50 18 90 Web site: http://www.ibs.fr/ *****************************************************************

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command line
by PC 09 Aug '14

09 Aug '14

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RNA 5' end needs 2 PO4s
by Phoebe A. Rice 08 Aug '14

08 Aug '14

I'm trying to model the first residue of an RNA, which has a di (maybe tri) phosphate on the 5' end I'm sure someone has already worked this out ... should we call the 1st residue GDP or GTP, and somehow tell phenix about the bond to residue #2 (how?) or should we add pyrophosphate to the default 5' phosphate? PS - as a side point, elbow generates GMP with no phosphate thanks, Phoebe

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CIF for Thiol-substituted DNA
by Mark A. White 06 Aug '14

06 Aug '14

Hello, I have a diThiol substituted phosphate on a CYT residue (C2S: S1P & S2P in place of O1P & O2P). So far I have tried using phenix.elbow to produce a CIF, but with limited success. First, the links to the neighbouring nucleotides are not created. I could just add a links.cif to the input, but this would not include the DNA angle restraints. Second, the sugar-base chirality is not preserved, although it is listed in the CIF file. Is there a better way to produce a substituted DNA, similar to the example of adding the O5T to 5pho GUA? Also, why is the sugar-base chirality not preserved if it is in the CIF? C2S chir_03 C1' O4' N1 C2' positiv the comand: phenix.elbow --do-all dt15_C.pdb produced: elbow.C2S.dt15_C_pdb.001.cif Thanks, Mark -- Yours sincerely, Mark A. White, Ph.D. Associate Professor of Biochemistry and Molecular Biology, Manager, Sealy Center for Structural Biology and Molecular Biophysics Macromolecular X-ray Laboratory, Basic Science Building, Room 6.660 C University of Texas Medical Branch Galveston, TX 77555-0647 Tel. (409) 747-4747 Cell. (281) 734-3614 Fax. (409) 747-1404 mailto://[email protected] http://xray.utmb.edu QQ: "All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Noel Adams (2002)

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