- phenixbb - phenix-online.org

real_space_correlation
by Jianghai Zhu 28 Feb '13

28 Feb '13

Hi All, I was trying to use "phenix.real_space_correlation *.pdb resolve_composite_map.mtz" to get some real space cc for my ligand against the SA composite omit map. But I am not sure that the map used here was the SA composite omit map. Will phenix use the omit map I provided or will it just simply calculate a sigmaA weighted 2Fo-Fc map based on the pdb? Thanks. --Jianghai

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mr_rosetta: two proteins, one chain placed, build second chain
by Tobias Beck 28 Feb '13

28 Feb '13

Dear phenixbb, I would like to use mr_rosetta to build a second protein chain. For the first protein, I have a search model with known structure. The search model can be placed with Phaser (TFZ 10). For the second protein, the structure of a homologue has been determined. The second protein accounts for about 2/3 of the residues in the ASU. I would like to fix the first protein chain and build the second protein chain with mr_rosetta. I have obtained fragment files for both proteins from robetta. What input parameters are required to tell mr_rosetta to build the second chain only? I have tried the fixed_ensemble_ID_list = ensemble1 option. Here is an excerpt of my parameter file with the input files: run a) search_models = "path/chainA.pdb" (from Phaser) search_models = "path/chainB.pdb" (homologue structure) fixed_ensembles { fixed_ensembleID_list = ensemble1 fixed_euler_list = 0.0 0.0 0.0 fixed_frac_list = 0.0 0.0 0.0 fixed_frac_list_is_fractional = True } alignment_files = "path/chainA.dat" alignment_files = "path/chainB.dat" with chainA.dat having twice the same sequence and chainB.dat with the target and template alignment. I have set fragment files with chain_list for both chains. I get this error when running phenix.mr_rosetta (running from command line with .eff file) "Sorry, the file /path/GROUP_OF_PLACE_MODEL_1/RUN_2/chainB_al_0.pdb representing group 0 has no atoms? This could indicate a problem with sequence alignment in rebuilding. It could be that there are near-duplicate sequences in your sequence file ...if this is the case then you may need to artificially rename your duplicated chains and renumber residues to make a single chain containing a duplication" This error also occurs run b) Without any alignment files run c) Without any alignment files and with just chainA.pdb as search model. An alignment of the sequences from chainA and chainB gives low identity (no duplicate regions), so I suspect the problem is located somewhere else? I have seen a post by Tom Terwilliger, explaining how to deal with two identical chains with different conformations where no alignment files are required. However, I would like to use the information from the homologue structure, that is why I specified the alignment file. By inputting chainB.pdb as search model, mr_rosetta also tries to use this model as a search model for molecular replacement, but I think this is not necessary (and gives a warning that the space group of the search model and the data file do not match). I just want to provide the structural information from structure chainB.pdb to mr_rosetta for building. ----- So in summary this is what I would like to do: chain A: keep fixed - use chainA.pdb as fixed model chain B: build - use information from homologue structure (chainB.pdb) and fragment files to build chain What is the best strategy to do this? What input parameters are required so that I do not get the error described above? ----- Thanks a lot in advance, Tobias.

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phaser output and packing
by Ursula Schulze-Gahmen 26 Feb '13

26 Feb '13

Could somebody explain to me how phaser decides if there is a solution. When I look at the log file there are a few solutions in the translation function that have fewer than the allowed clashes, but they are still not recognized as potential solutions. Why is that. Is there another parameter that I should be looking at? Ursula -- Ursula Schulze-Gahmen, Ph.D. Assistant Researcher UC Berkeley, QB3 356 Stanley Hall #3220 Berkeley, CA 94720-3220

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WCPCW 21
by Williams, John Charles 22 Feb '13

22 Feb '13

All, We will be finalizing the program for the workshop on Monday, Feb 25th. The Monterey Plaza and Spa has confirmed that we can accommodate a few more people. So, if you are interested in attending and would like to be considered for an oral presentation or would like to present a poster, please register and submit an abstract no later than Monday, 12 noon (PST). The meeting will be March 17th-20th with Wayne Hendrickson as the Keystone speaker! Best, John wcpcw.org --------------------------------------------------------------------- *SECURITY/CONFIDENTIALITY WARNING: This message and any attachments are intended solely for the individual or entity to which they are addressed. This communication may contain information that is privileged, confidential, or exempt from disclosure under applicable law (e.g., personal health information, research data, financial information). Because this e-mail has been sent without encryption, individuals other than the intended recipient may be able to view the information, forward it to others or tamper with the information without the knowledge or consent of the sender. If you are not the intended recipient, or the employee or person responsible for delivering the message to the intended recipient, any dissemination, distribution or copying of the communication is strictly prohibited. If you received the communication in error, please notify the sender immediately by replying to this message and deleting the message and any accompanying files from your system. If, due to the security risks, you do not wish to receive further communications via e-mail, please reply to this message and inform the sender that you do not wish to receive further e-mail from the sender. (fpc5p) ---------------------------------------------------------------------

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Maximum Entropy Maps
by Morten Groftehauge 22 Feb '13

22 Feb '13

Hi guys, I see that phenix.maximum_entropy_map is now a command in Phenix. Some quick questions: Where is this likely to be must useful and does it take ridiculously long to run? From the Nishibori 2008 paper in Acta D it seems like this would mainly be useful for very high resolution structures that you would normally call complete - and that it would take a very long time to compute. I love trying out new methods but I need a bit more to go on with this one. Cheers, Morten -- Morten K Grøftehauge, PhD Pohl Group Durham University

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Building sugars
by Folmer Fredslund 21 Feb '13

21 Feb '13

Dear all, What's the "correct" way to build and refine sugar polymers? I am currently building several structures with different kinds of sugar polymers bound to them. Searching for similar "ligands" in the PDB, I end up with e.g. trisaccharides that are named as one molecule, even though they are indeed made up of three individual sugars with bonds between them. Thank you for any pointers. Best regards, Folmer -- Folmer Fredslund

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phenix.table_one citation
by Alexander Batyuk 20 Feb '13

20 Feb '13

Dear developers, How to cite phenix.table_one? Best wishes, Alex -- Alex Batyuk The Plueckthun Lab www.bioc.uzh.ch/plueckthun

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cut out density vs FFT
by Yunji Wu 19 Feb '13

19 Feb '13

Hi all-- I'm trying to make a 2Fo-Fc map with density wrapped around my asymmetric unit to make a figure showing density for my sub-8Å structure. I am not building into this map or doing MR. My model was refined in Phenix.refine (R's in the high 30's), and so I have the output model .pdb and the output map coefficients .mtz. When I input these into cut_out_density, the only "map labels" input options it gives me are 2FOFCWT, PH2FOFCWT, which seem fine. Using either box, sphere, or model for the cutout type, I get a VERY nice looking map that looks extremely solvent flattened and tight around my model, albeit still to 8Å. Suspicious of anything that looks good, I went to try the same thing in FFT (CCP4). There I generated a simple map (using the same .mtz) to cover all atoms in a pdb file- the same model I put into cut_out_density. For the input I selected 2FOFCWT and PH2FOFCWT, leaving Sigma and Weight unassigned. The map that comes out of this looks terrible, with a lot of noise and little density corresponding to the model aside from what one might expect from a very poor resolution experimental map. I've also tried using FFT in Phenix to do the same thing, and it gives like better maps than CCP4 FFT but worse than cut_out_density. It almost appears as if there is some additional solvent flattening going on, which I know happens at the beginning of refinement, but that should be intrinsic to the map coefficients file which is common to everything I've tried. My questions are (1) what should I use for what I am trying to do (just display 2Fo-Fc density around asymmetric unit for a figure) and (2) what is the difference between what these three programs (cut_out, FFT-CCP4, FFT-Phenix) are calculating? The inputs are exactly the same -- mtz (2FOFCWT and PH2FOFCWT) and pdb output from refinement. Thanks for the help, Yunji

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Problems placing second component in Phaser
by Morten Groftehauge 19 Feb '13

19 Feb '13

Hi guys, So I have a solution that covers some of target and I ran it through phenix.mr_rosetta and I am actually kinda happy with the output from there. However, while I can place both (NCS=2) with the original model I only seem to be able to place one of the rosetta models, even with 'packing function' set to 'all' or 'allow'. Original model - Refinement after placing component 1: LLG 175 Refinement after placing component 2: LLG 620 Rosetta model (packing 'all') - Refinement after placing component 1: LLG 295 Refinement after placing component 2: LLG 390 Rosetta model (packing standard) - Refinement after placing component 1: LLG 295 Refinement after placing component 2: LLG 350 More notably there is little to no increase in TFZ with the placement of the second component... There are more residues in the Rosetta model and I would expect more clashes but this looks weird. Cheers, Morten -- Morten K Grøftehauge, PhD Pohl Group Durham University

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where is brute rotation output
by Ursula Schulze-Gahmen 18 Feb '13

18 Feb '13

Hi, Has anybody experience with the output from the brute rotation function. I ran this and it finished without complaints, but there are no output files ***.rlist or ***.sol in the directory. I cannot figure out why and how to continue now with the translation function. From the log file it seemed that there were peaks that could have been written out. Thanks for any help Ursula -- Ursula Schulze-Gahmen, Ph.D. Assistant Researcher UC Berkeley, QB3 356 Stanley Hall #3220 Berkeley, CA 94720-3220

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Phaser problem for flexible domain of protein
by Appu kumar 18 Feb '13

18 Feb '13

Dear user, I have problem in finding the phase for the flexible DNA binding domain of LTTR protein. The unit cell parameters are ,Unit Cell: 46.92 105.30 47.75 90.00 103.26 90.00, and space-Group P 1 21 1. Molecular weight of protein is 36000Da. When i am running phaser it showing that Most probable MW of protein in asu for resolution = 49714.8. Could you please guide me how to set the proper setting for finding the correct rotation function and translation function setting to get the phases for the full length protein. I m getting the phases for the ligand binding domain but not for the DNA binding domain. Could you please suggest me some tricks which would work to get the phase. Thanks a lot in advance. Appu

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Trouble with Phenix
by Rachel North 17 Feb '13

17 Feb '13

Hi, I have been having some issues with Phenix. When I input the mtz file (generated from CCP4), an error message appears... "File format error: cctbx Error: invalid combination of values while extracting anomalous array from columns: F New, SIGF New, DANO New, SIGDANO New, hkl= -3,25,44." This happens when I try to use the reflection file editor, xtriage and phenix refine. I have tested datasets collected from other crystals in the same condition and still have the same problem. I have also tried to process my data using different programs (XDSME and iMOSFLM) before going to CCP4 and then Phenix for refinement. I have never had this problem before and I have run every program on CCP4 the same way that I usually do. Does anyone know how I fix this or where I am going wrong? Kind Regards

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how to make covelent link of BME with Cys and refine
by Rajeshwer Sankhala 15 Feb '13

15 Feb '13

Hello Nat, Thank you so much for your suggestion. I did run phenix refinement in nightly build phenix version with " intra_chain = True " command. This time refinement worked but again in out put pdb no disulfide bond is estabilished between cys and BME. I provided .pdb, .mtz and .cif files as input. Well can you please suggest me how i can provide both BME and Cys-BME (SS bond) restrains in .cif file? if that happens then i feel refinement should work. I am attaching my .cis file below please have a look and tell me if anything wrong with this? BME.cif # electronic Ligand Builder and Optimisation Workbench (eLBOW) # - a module of PHENIX version 1.8.1-1168 (Mon Sep 28 16:48:00 2012) # - file written: Sat Jan 26 17:25:31 2013 # # Input file: Ref226_154-331-VLD2-BME.pdb # Random seed: 3628800 # Residue: BME # data_comp_list loop_ _chem_comp.id _chem_comp.three_letter_code _chem_comp.name _chem_comp.group _chem_comp.number_atoms_all _chem_comp.number_atoms_nh _chem_comp.desc_level BME BME 'Unknown ' ligand 10 4 . # data_comp_BME # loop_ _chem_comp_atom.comp_id _chem_comp_atom.atom_id _chem_comp_atom.type_symbol _chem_comp_atom.type_energy _chem_comp_atom.partial_charge _chem_comp_atom.x _chem_comp_atom.y _chem_comp_atom.z BME S S S2 . -19.3229 -20.3986 17.2400 BME H5 H H . -18.1988 -20.0550 17.0819 BME C1 C CH2 . -19.3558 -21.8852 18.1928 BME H3 H HCH2 . -18.8480 -21.7572 19.0093 BME H4 H HCH2 . -18.9637 -22.6079 17.6781 BME C C CH2 . -20.7668 -22.2261 18.5333 BME H1 H HCH2 . -21.1200 -21.5643 19.1482 BME H2 H HCH2 . -20.7965 -23.1021 18.9488 BME O O OH1 . -21.5280 -22.2370 17.3822 BME H H HOH1 . -22.3435 -22.5247 17.5704 # loop_ _chem_comp_bond.comp_id _chem_comp_bond.atom_id_1 _chem_comp_bond.atom_id_2 _chem_comp_bond.type _chem_comp_bond.value_dist _chem_comp_bond.value_dist_esd BME S H5 single 1.186 0.020 BME S C1 single 1.766 0.020 BME C1 H3 single 0.970 0.020 BME C1 H4 single 0.970 0.020 BME C1 C single 1.491 0.020 BME C H1 single 0.970 0.020 BME C H2 single 0.970 0.020 BME C O single 1.380 0.020 BME O H single 0.885 0.020 # loop_ _chem_comp_angle.comp_id _chem_comp_angle.atom_id_1 _chem_comp_angle.atom_id_2 _chem_comp_angle.atom_id_3 _chem_comp_angle.value_angle _chem_comp_angle.value_angle_esd BME C1 S H5 109.48 3.000 BME C C1 H4 109.47 3.000 BME C C1 H3 109.47 3.000 BME H4 C1 H3 109.47 3.000 BME C C1 S 109.47 3.000 BME H4 C1 S 109.47 3.000 BME H3 C1 S 109.47 3.000 BME O C H2 109.47 3.000 BME O C H1 109.47 3.000 BME H2 C H1 109.47 3.000 BME O C C1 109.47 3.000 BME H2 C C1 109.47 3.000 BME H1 C C1 109.47 3.000 BME H O C 109.48 3.000 # loop_ _chem_comp_tor.comp_id _chem_comp_tor.id _chem_comp_tor.atom_id_1 _chem_comp_tor.atom_id_2 _chem_comp_tor.atom_id_3 _chem_comp_tor.atom_id_4 _chem_comp_tor.value_angle _chem_comp_tor.value_angle_esd _chem_comp_tor.period BME Var_01 O C C1 S 52.25 30.0 3 BME Var_02 H1 C C1 S -67.75 30.0 3 BME Var_03 H2 C C1 S 172.25 30.0 3 BME Var_04 O C C1 H3 172.25 30.0 3 BME Var_05 O C C1 H4 -67.75 30.0 3 # loop_ _chem_link.id _chem_link.comp_id_1 _chem_link.mod_id_1 _chem_link.group_comp_1 _chem_link.comp_id_2 _chem_link.mod_id_2 _chem_link.group_comp_2 _chem_link.name CYS-BME CYS DEL-HG . BME DEL-HS . SS-bridge # Thanks

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HETATM automated chain assignment
by Talon Romain 15 Feb '13

15 Feb '13

Hello to the Phenix bulletin board community, I would like to know if I could find a tool to automatically assign HETATM atom (or even, water molecules) to the nearest protein chain ? In my case, I have 4 protein chains in the asymmetric unit : A, B, C and D. I would like to assign each ions and each ligands (which are numerous) with the chain letter of the nearest residue that coordinate them. Usually, I rename everything by hand but as the in-house program of the PDBe AutoDep deposition tool automatically do that... I beg your pardon if this question has just been posted here. I didn't find any tool either in the Phenix Suite or in the "Extensions" and "Calculate" menus of the Coot program (v0.7). Best regards. Romain Talon

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how to make covelent link of BME with Cys and refine
by Rajeshwer Sankhala 13 Feb '13

13 Feb '13

Hello Sabine Yah i could specify link in the pdb and also could see it in coot but when i go for refinement then bond is broken. I given pdb mtz and cif files in refinement. The only problem i feel could be that i don't have restrains for SS bond in cif file but i don't know how to generate SS-bond restrains. Thanks RAJ

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how to make covelent link of BME with Cys and refine
by Rajeshwer Sankhala 13 Feb '13

13 Feb '13

Thanks Nigel, I am using phenix 1168 but when i type intra_chain = True command with phenix.refine it gives error message as "intra_chain = True is unknown command". The actual command i used was " phenix.refine .pdb .mtz .cif intra_chain = True". can you please explain how to resolve it. Raj

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Re: [phenixbb] how to make covelent link of BME with Cys and refine
by Ed. Pozharski 13 Feb '13

13 Feb '13

Excellent point. The difference between using bme and cme is rather ideological. I would say that incorporating cme implies that your protein was somehow synthesized with non-canonical amino acid. Usind bme seems more in line with what actually happens - betamercaptoethanol forming disulfide bond with a cysteine. In practical sense, both things work. Until IUCr comes up with a convention, one is free to ignore ideological considerations :) -------- Original message -------- From: Abhinav Kumar <abhinavk(a)slac.stanford.edu> Date: To: phenixbb(a)phenix-online.org Subject: Re: [phenixbb] how to make covelent link of BME with Cys and refine How about using residue CME which is the CYS and BME linked together. CME is included in the CCP4 monomer library, and so Phenix should accept it without a dictionary file. Thanks, Abhinav JCSG@SSRL, SLAC (650) 926-2992 On 02/13/2013 01:02 PM, Nigel Moriarty wrote: Raj In the more recent versions of PHENIX, phenix.refine can found and link atoms closer than 3 angstrom if you specify intra_chain=True. In the older versions, you can use phenix.ligand_linking to generate the needed files. Nigel PS PHENIX does not read SSBOND or LINK records but there is a script to generate the link files from the LINK records. On Tue, Feb 12, 2013 at 11:56 PM, Sabine Schneider <sabine.schneider(a)mytum.de> wrote: Hello Raj, do you have the link specified in you PDB file? Here is an example for an disulphide bond. Usually the link is the line above the CRYST1 card. SSBOND 1 CYS A 123 CYS A 123 1555 8555 2.12 Best, Sabine On 02/12/2013 11:21 PM, Rajeshwer Sankhala wrote: Hello, I can see additional density just next to Cys residues in my protein structure and it looks like BME is covalently linked to cys. I could form a disulfide bond between BME and Cys in "Refmac 5 review restrain" but when i subject it for refinement BME is thrown away (no disulfide bond). I also given Cif file in refinement but it didnot help. I have a feel that i am missing something in cif file. Can anyone suggest step by step starting from adding BME to making a link with BME (Cys-BME) and then refinement? Raj _______________________________________________ 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 -- Nigel W. Moriarty Building 64R0246B, Physical Biosciences Division Lawrence Berkeley National Laboratory Berkeley, CA 94720-8235 Phone : 510-486-5709 Email : NWMoriarty(a)LBL.gov Fax : 510-486-5909 Web : CCI.LBL.gov

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how to make covelent link of BME with Cys and refine
by Rajeshwer Sankhala 13 Feb '13

13 Feb '13

Hello, I can see additional density just next to Cys residues in my protein structure and it looks like BME is covalently linked to cys. I could form a disulfide bond between BME and Cys in "Refmac 5 review restrain" but when i subject it for refinement BME is thrown away (no disulfide bond). I also given Cif file in refinement but it didnot help. I have a feel that i am missing something in cif file. Can anyone suggest step by step starting from adding BME to making a link with BME (Cys-BME) and then refinement? Raj

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How to export difference patterson map in PHENIX
by 李翔 12 Feb '13

12 Feb '13

Hi everyone, I got a native and derivative dataset (by soaking) of my crystal and want to do MIR in phenix. I am wondering whether there is a way for me to export the difference Patterson map so I could have a better idea that whether the heavy atom is really in the crystal? Cheers, Frank

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fwd: WCPCW 21 - Abstract due...
by Nathaniel Echols 11 Feb '13

11 Feb '13

---------- Forwarded message ---------- From: "Williams, John Charles" <jwilliams(a)coh.org> To: "PHENIX user mailing list" <phenixbb(a)phenix-online.org> Date: Mon, 11 Feb 2013 12:47:21 -0800 Subject: WCPCW 21 - Abstract due... Dear All, March 17th is coming up soon. Looks like we have a great crowd and some really good abstracts. Those who havent submitted their abstracts are encourged to do so now. We will start to select talks shortly there after. Those who would like to still attend are encouraged to sign up - we still have space. Looking for to seeing you on St. Patty's day! Best, John

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FW: phenixbb Digest, Vol 87, Issue 3
by Phoebe A. Rice 10 Feb '13

10 Feb '13

Hi, Although its theoretically possible, I've never had 5-Br-dU cause a problem. My approach would be to pick the strand with more T's and get every T replaced with 5-Br-dU, unless the 3' nt is a T (you pay a lot more for 3' modifications). We have had issues where crystals wouldn't grow with a heavily 5-I-dU modified DNA, presumably because Iodine is significantly bigger than a the 5-methyl of T, and it annoys the protein. If you've got good footprinting data, you may be able to guess where the protein will "care" about the surface of the major groove, and avoid putting iodines in those regions. If not, its probably faster to just order several oligos and try them all. If you've got a lot of T's and are worried about locating all those heavy atoms, I'd go for one derivative with a couple of paired 5-I-dU's (in spots where you have two T's in a row) in hopes that that will give you a toehold on solving the Patterson, and then a 2nd where every T on one strand is brominated, which may provide more phasing power. Note that both of these pop off in the x-ray beam, so collect your anomalous data first and fast. Also note that if you're lucky, you can get an extra large delta f' by subtracting the last data set from the first ("radiation induced phasing"). Hope that helps! Phoebe ++++++++++++++++++++++++++++++++++++++++++ Phoebe A. Rice Dept. of Biochemistry & Molecular Biology The University of Chicago 773 834 1723; PRice(a)uchicago.edu http://bmb.bsd.uchicago.edu/Faculty_and_Research/ http://www.rsc.org/shop/books/2008/9780854042722.asp

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CeBEM-CCP4 Macromolecular Crystallography Workshop 2013 at Montevideo: Application deadline extended
by Alejandro Buschiazzo 08 Feb '13

08 Feb '13

Dear Colleagues, Due to the application deadline originally scheduled for February 10, overlapping with Summer holiday dates in several South American countries, we have decided to extend the course application deadline UNTIL FEBRUARY 17, 2013. We invite all of you interested in this workshop, especially the ones that have contacted us, to take advantage of this opportunity and send your application forms (plus CV and letter of your supervisor): last days for applications open!! Find all details about the workshop and application form in www.pasteur.edu.uy/mx2013 <http://www.pasteur.edu.uy/mx2013>- for further inquiries and applications contact mx2013(a)pasteur.edu.uy <mailto:[email protected]>! *Second Macromolecular Crystallography School 2013 *at the Institut Pasteur de Montevideo (Uruguay). *Title:* "Macromolecular Crystallography School 2013: From data processing to structure refinement and beyond" *Dates:*April 9th-17th, 2013. *Site:*Institut Pasteur de Montevideo (Montevideo), Uruguay *The workshop content:* Conceived to provide theoretical background and hands-on abilities in the use of computational tools to exploit X ray diffraction data. Through lectures, tutorials and hands-on trouble-shooting, the students will be trained in state-of-the-art macromolecular crystallography. Particular emphasis will be given to data processing, phasing/structure determination and model refinement/validation. The workshop will feature authors and experts of many modern crystallographic software packages. This workshop represents the continuation within the series started in 2010 (http://www.pasteur.edu.uy/mxcourse) on Macromolecular Crystallography. In this opportunity it is being co-organized by the Center for Structural Biology of the Mercosur CeBEM (www.cebem.org.ar <http://www.cebem.org.ar>), jointly with the Collaborative Computational Project Number 4 (CCP4 -- UK www.ccp4.ac.uk <http://www.ccp4.ac.uk>). Support from the Institut Pasteur International Network, the International Union of Crystallography and Institut Pasteur de Montevideo is also greatly acknowledged. *Applicants:* Graduate students, postdoctoral researchers and young scientists are encouraged to apply. Only 20 applicants will be selected for participation. Participants of the workshop are strongly encouraged to bring their own problem data sets so they can be used during the workshop's hands-on sessions. There is no registration fee. Support for accommodation, per diem and local transportation will be provided to all participants from abroad. Support to cover travel expenses will be considered on a case-by-case basis. Specific requests should be well-grounded as we will only be able to select a limited number. *Application:* Application *deadline has now been extended until February 17, 2013*. Application form, the program, contact info and other details can be found at www.pasteur.edu.uy/mx2013 <http://www.pasteur.edu.uy/mx2013> Please address further inquiries to mx2013(a)pasteur.edu.uy <mailto:[email protected]> Ronan Keegan and Alejandro Buschiazzo -- Alejandro Buschiazzo, PhD Research Scientist Unit of Protein Crystallography Institut Pasteur de Montevideo Mataojo 2020 Montevideo 11400 URUGUAY Phone: +598 25220910 int. 120 Fax: +598 25224185 http://www.pasteur.edu.uy/pxf

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phaser for long thin molecule
by Ursula Schulze-Gahmen 08 Feb '13

08 Feb '13

I am doing molecular replacment for a very elongated molecule in phaser. I would like to try different values for the maximum patterson cutoff but I am not sure which parameter I need to change in the phenix version of phaser. Does somebody have experience with this? Thanks Ursula -- Ursula Schulze-Gahmen, Ph.D. Assistant Researcher UC Berkeley, QB3 356 Stanley Hall #3220 Berkeley, CA 94720-3220

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How to model domain-wide disorder in Phenix.refine (turn off bump interactions) ?
by Phil Jeffrey 08 Feb '13

08 Feb '13

Hi, I've got a pernicious problem where the electron density for one domain appears to extensively interpenetrate another similar domain. I'm in the process of trying to work out things like: MR solution in the wrong space group courtesy of pseudo-centering. In the meanwhile I want to model it as interpenetrating domains, and need to turn off VdeW bumps at the domain (chain) level of structure. I can't just model it as a infinite list of alternate locations. I (think) I remember how to do this in CNS (constraints interaction), but is there a way to do this in phenix ? I could not track down a particularly promising section of either the manual or the .def/eff file(s). Thanks Phil Jeffrey Princeton

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Designing heavy atom positions on my DNA crystal
by Xiang Li 06 Feb '13

06 Feb '13

Hi everyone, I am trying to grow my DNA crystal with bromide derivatives. The content in one asymmetric unit is a 30 bp DNA duplex. I am considering about how many bromides modified bases should I use to ensurethe strong enough heavy atom signal. Also where to put these bromides? To my understanding, maybe I should put the heavy atoms at the most rigid places, avoiding the clashes and not too close to other heavy atoms. I have few experience on this and hope you could give me some help on the design. Thanks a lot! Sincerely, Xiang

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