June 2015 - phenixbb - phenix-online.org

Model bias in MR-SAD
by mohamed noor 05 Jun '15

05 Jun '15

Dear all In the case of MR-SAD, how bad can model bias be? Does it also depend on the data resolution and resolution at which there is still enough anomalous signal? Or can the anomalous signal help in overcoming the bias inherent in the MR model? Thanks.

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R free assignment in thin shells
by mohamed noor 04 Jun '15

04 Jun '15

Dear all I found a not-so-old thread about this topic: http://phenix-online.org/pipermail/phenixbb/2012-January/018259.html. Maybe there has been significant changes in phenix.refine since then. However, I couldn't find a conclusion. In my case, my data extends to 1.4 A with the R/R free being around 23/26 %. There is also pseudo symmetry, so there are 16 NCS copies in a lower symmetry group than what Xtriage suggested. The map looks fine with density for some H atoms even being visible. On what basis should I decide whether to use (or not) thin shell assignment? And what is the cut-off for number of NCS copies? Thanks.

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Problems running phenix.rosetta_refine
by Klose, Thomas 04 Jun '15

04 Jun '15

Dear all, I was trying to set up phenix.rosetta_refine to test it for the refinement of a 4.5Å structure. I installed the latest phenix release and compiled the latest rosetta version (2015.19) using rosetta.build_phenix_interface. However, when I try to run phenix.rosetta_refine I get the following error message: …. Generating 5 models on 4 processors... DEBUG dumping error message ERROR: Rosetta exited with status 1 stderr output: Sorry: Wrong map type requested: %%map_type%% Allowed format is: [p][m]Fo+[q][D]Fc[kick][filled] where [p] and [q] are any numbers (optional), [m] and [D] indicate if the requested map is sigmaa (optional), Fo and Fc are Fobs and Fcalc, [kick] is for Average Kick Map (optional), [filled] is for missing Fobs filled map. Examples: 2mFo-DFc, 3.2Fo-2.3Fc, mFobs-DFcalc_kick, 2mFobs-DFcalc_filled, Fc, 2mFobs-DFcalc_kick_fill, anom, anom_diff, anomalous_difference, Fo ERROR: PhenixInterface::calculateDensityMap() : error writing map ERROR:: Exit from: src/core/scoring/cryst/PhenixInterface.cc line: 1122 This happens with our actual data as well as test data that I downloaded (PDB: 1yip). Any help in solving this problem would be greatly appreciated. Thanks, Thomas

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Help with using FFT map coefficients tool
by Emilia C. Arturo (Emily) 04 Jun '15

04 Jun '15

Hello. I'd like to generate a map appropriate for viewing in PyMOL, using a model and structure factors downloaded from the PDB. But I'm unable to do so, and perhaps you can help me figure out what I might be doing wrong: To generate the map, I did the following using the phenix GUI (version 1.9-1692): 1. I used Reflection tools > Import CIF structure factors to convert the .cif format structure factors for PDB id 1J8U to an mtz file. 2. Then, to configure the job to generate the CCP4 map, I loaded this mtz file, but when I did that I got the following error: "This reflections file does not appear to contain any suitable map coefficients" I went through the same steps again for two other PDB ids, this time generating the mtz file by either letting phenix do it from a PDB id, or by supplying the tool with both a .cif file with structure factors and a pdb model file. I get the same error. Has anyone any advice? Regards, Emily.

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Re: [phenixbb] Changing an amino acid to an unusual amino acid
by Schubert, Carsten [JRDUS] 03 Jun '15

03 Jun '15

Hi Nat, bonds in COOT do not mean much, as they do not translate into bonded interactions in the refinement programs. Phenix for instance tries to figure out the bonding by itself through some distance based heuristics. However in your case it looks as if the CRO residue may not be defined as a polymer, i.e. part of a protein chain in the monomer library you are using. In Windows the monomer library is located in C:\WinCoot\share\coot\lib\data\monomers. Look at the difference in the headers for CYS.cif and CRO.cif or PTR.cif (phosphotyrosine). The aminoacids or modified aminoacids considered part of the peptide chain have all 'peptide' in the header, CRO does not. That is probably the reason why coot does not make any bonds. This would probably cause problems later on with Phenix as well. You could pull out the CRO.cif into your directory, modify it to make it a peptide and read it into coot and phenix during refinement. I would also run it through REEL to make sure the definitions are kosher. HTH Carsten From: Natalia Ketaren [mailto:[email protected]] Sent: Tuesday, June 02, 2015 5:42 PM To: Schubert, Carsten [JRDUS] Subject: Re: Changing an amino acid to an unusual amino acid Hi Carsten, Th residue is a part of the correct chain. It just doesn't make an bonds with the residues on either side of it. Is this common for unusual amino acids when adding to the main chain? Cheers, Nat _____________________________ Natalia E. Ketaren, PhD Postdoctoral Associate Rout Laboratory Box 213 The Rockefeller University 1230 York Avenue New York, NY 10065 Tel: (212) 327-8136 Fax: (212) 327-7193 Natalia.Ketaren(a)rockefeller.edu<mailto:[email protected]> website: http://lab.rockefeller.edu/rout/ NCDIR: http://www.ncdir.org/ On Jun 2, 2015, at 5:26 PM, Schubert, Carsten [JRDUS] <CSCHUBER(a)its.jnj.com<mailto:[email protected]>> wrote: Hi Natalia, if the missing/wrong chain IDs are really the problem you can change them in COOT under Calculate -> Change Chain IDs. The dialog is a bit tricky, since you probably have to use the correct residue range to change an individual residue into an existing chain. In your case I would write out the PDB file and use a text editor to change the chain ID and move the residue into its correct place in the file. HTH Carsten From: phenixbb-bounces(a)phenix-online.org<mailto:[email protected]> [mailto:[email protected]] On Behalf Of Natalia Ketaren Sent: Tuesday, June 02, 2015 5:17 PM To: phenixbb(a)phenix-online.org<mailto:[email protected]> Subject: [phenixbb] Changing an amino acid to an unusual amino acid Hello All, I'm working on a GFP structure and I'm trying to incorporate the CRO (chromophore) residue into the structure using coot. My process is to use Extension->Modelling->Replace residues, where it's suppose to replace a Tyr residue. I type the 3 letter code, CRO, the residue appears, I'm able to real space refine it, but it does not incorporate CRO into the desired chain. Would someone be able to help me figure out what I'm doing wrong? And possibly walk me through a solution? Cheers, Nat _____________________________ Natalia E. Ketaren, PhD Postdoctoral Associate Rout Laboratory Box 213 The Rockefeller University 1230 York Avenue New York, NY 10065 Tel: (212) 327-8136 Fax: (212) 327-7193 Natalia.Ketaren(a)rockefeller.edu<mailto:[email protected]> website: http://lab.rockefeller.edu/rout/ NCDIR: http://www.ncdir.org/

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Negative density
by mohamed noor 03 Jun '15

03 Jun '15

Dear all After refinement, there is a single negative peak in my map where nothing is modeled. What does it mean? Thanks.

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Changing an amino acid to an unusual amino acid
by Natalia Ketaren 02 Jun '15

02 Jun '15

Hello All, I’m working on a GFP structure and I’m trying to incorporate the CRO (chromophore) residue into the structure using coot. My process is to use Extension->Modelling—>Replace residues, where it’s suppose to replace a Tyr residue. I type the 3 letter code, CRO, the residue appears, I’m able to real space refine it, but it does not incorporate CRO into the desired chain. Would someone be able to help me figure out what I’m doing wrong? And possibly walk me through a solution? Cheers, Nat _____________________________ Natalia E. Ketaren, PhD Postdoctoral Associate Rout Laboratory Box 213 The Rockefeller University 1230 York Avenue New York, NY 10065 Tel: (212) 327-8136 Fax: (212) 327-7193 Natalia.Ketaren(a)rockefeller.edu<mailto:[email protected]> website: http://lab.rockefeller.edu/rout/ NCDIR: http://www.ncdir.org/

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Merging reflections
by mohamed noor 02 Jun '15

02 Jun '15

Dear all I have a few native datasets, one anomalous dataset with signal up to 10 A and two other datasets (also collected at the phasing wavelength but no anomalous signal seems to be present) and a sulfur SAD dataset with signal to about 7 A. All the datasets have a resolution of about 2-3 A and processed with xia2/XDS. I couldn't do fluorescence scan as the detector couldn't detect at such a high energy (20 keV). A few questions: 1. Why is there at least some signal from one dataset but not others? The signal should come from a covalently bound ligand, molybdopterin to be precise. 2. Since I(+) should not be equal to I(-) when there is anomalous signal, should I just merge the native dataset together with those collected at phasing wavelength that have no anomalous signal? Or do I merge everything together? 3. Will the anomalous signal to 10 A be useful to do MR-SAD? I could solve the structure with MR but I wanted to be sure my ligand is there. Thanks.

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Allignment of multiple structures
by jens j birktoft 01 Jun '15

01 Jun '15

I apologize if this question this question has been asked before but I still need help finding an answer to the following. I am looking for a program/web-server that will calculate the superposition of multiple structures (non-protein!) Thanks -- +++++++++++++++++++++++++++++++++++++++++++++++++++ Jens J. Birktoft Structural DNA Nanotechnology Department of Chemistry New York University e-mail: jens.knold(a)gmail.com; Phone: 212-749-5057 very slow-mail: 350 Central Park West, Suite 9F, New York, NY 10025 +++++++++++++++++++++++++++++++++++++++++++++++++++

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a question on phenix.real_space_refine
by Smith Liu 01 Jun '15

01 Jun '15

Dear Pavel, By phenix.real_space_refine, I fit a PDB with a 4.0 map. Most of the fitting were nice, but for the Ala residues, it indicates the o of the C=O occupies the density position which should be occupied by the CH3 side chain of the Ala, which also means the CH3 side chain of Ala cannot occupy the density position which clearly should be occupied by the CH3 side chain of Ala. Is any method or restraint to have the CH3 of Ala to ccupy its density position? Smith

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