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Problem with rotamer refinement
by Renato Ferras 11 Jul '17

11 Jul '17

Dear all, I am refining a protein structure at 1.74 A resolution with phenix.refine (version 1.10.1_2155) and I have noticed that some side chains don't remain in the electronic density even after careful hand adjustment in which they are almost perfect. It seems pretty clear where the side chain should (must) be located, moreover it is consistent with two rotamers (either rotamer tp60 - #4 in coot - or rotamer tp-100 - #9 in coot -, which are approx. at 180 deg for chi3). In spite of that, after reciprocal space refinement, I observe that the end of side chain rotates chi3 angle and both N and O gets far from where they started (there is this difference in the chi3 angle). My concerns are about the proper interpretation of geometrical restraints listed in .geo file, specially what the ideal value is, how weights are applied to ideal value and why phenix doesn't reach convergence in reciprocal space refinement. Below are the values from .geo for the referred Gln: dihedral pdb=" CB GLN B 21 " pdb=" CG GLN B 21 " pdb=" CD GLN B 21 " pdb=" OE1 GLN B 21 " ideal model delta sinusoidal sigma weight residual 0.00 23.41 -23.41 2 3.00e+01 1.11e-03 8.42e-01 is there a description for us to interpret what these numbers are? To my understanding, the ideal values are established as being either 0 or 180 degrees (yet sinusoidal 2). I cannot say about how heavy the weights are on these (in fact, I left my refinement to optimize weights), but anyway, if I understand correctly, the ideal value (for chi3) should be rotamer dependent. Taking Gln as an example, I see several rotamers do have values close to either 0 or 180 degree, but what about rotamers 4 and 9? I might imagine a similar situation for residues like Asn and His, though I have not searched deep for these yet. Thanks, Renato

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crystal imaging system
by Sebastiano Pasqualato 30 Jun '17

30 Jun '17

Dear all, we are in the process of considering the purchase of a new Crystal Imager. So far, we have been considering the Formulatrix Rock Imager 182 and the TriTek Crystal Pro HT. I would be extremely grateful to anyone who could provide me: - feedback and user experience (positive/negative) on those instruments; - information on other instruments you would suggest. Thank you very much in advance, wishing you a pleasant weekend, best regards, ciao, S -- Sebastiano Pasqualato, PhD Crystallography Unit Department of Experimental Oncology European Institute of Oncology IFOM-IEO Campus via Adamello, 16 20139 - Milano Italy tel +39 02 9437 5167 fax +39 02 9437 5990 web http://is.gd/IEOXtalUnit

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Phenix polder error
by Avinash Punekar 26 Jun '17

26 Jun '17

Dear all, When I run phenix.polder through command line, I get a message "Sorry: Multiple equally suitable arrays of observed xray data found." and phenix.polder stops without producing the maps. How to solve this problem? Any help is highly appreciated. Thanks, Avinash

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does phenix refine fill in missing data?
by Ursula Schulze-Gahmen 22 Jun '17

22 Jun '17

I have very anisotropic data. I used the staraniso webserver to analyse and process my data which creates a final merged file with very incomplete data in the outer shells. If I use this data file in Phenix, what will happen? Will Phenix automatically fill in the unobserved data? If so, can I prevent it from doing so? I am importing the data with the reflection file editor and it seems the reflections are being filled in already at this stage. Ursula -- Ursula Schulze-Gahmen, Ph.D. Project Scientist UC Berkeley, QB3 360 Stanley Hall #3220 Berkeley, CA 94720-3220 (510) 643 9491

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Cif file recognition
by Joel Tyndall 21 Jun '17

21 Jun '17

Hi there, Having a few minor issues with my phenix setup on windows 10. I have the latest stable build Phenix1.11.1-2575. When introducing a new ligand that exists in the monomer library, Pheix complains it does not have the geometry restraints (cif file) - somehow it is not seeing its own library. How can I set up the cif library as default? Cheers Joel Joel Tyndall | BSc(Hons) PhD Associate Professor in Medicinal Chemistry School of Pharmacy | Te Kura Mātauraka Wai-whakaora University of Otago | Te Whare Wānanga o Otāgo PO Box 56 9054 Dunedin | Ōtepoti New Zealand | Aotearoa Ph: 64 3 479 7293 Skype: jtyndall Website | pharmacy.otago.ac.nz

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sculptor modifications
by Emilia C. Arturo (Emily) 21 Jun '17

21 Jun '17

Hello All, Is there a way to identify quickly the changes to a model that Sculptor has made? I am running the Phenix GUI to use Sculptor. I have read through the out-put log file, and understand (mostly) the sculpt protocol as it relates to the circumstances under which modifications to main chain or side chains are made, but it would be nice to see (in a list format, perhaps) what changes (if any...) were made. Regards, Emily. -- "Study as if you were going to live forever; live as if you were going to die tomorrow." - Maria Mitchell "I'm not afraid of storms for I'm learning to sail my ship." - Louisa May Alcott

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phenix.map_to_model input mtz file failure
by dancingdream＠163.com 18 Jun '17

18 Jun '17

Dear Phenix bb, I intend to build a initial model by phenix.map_to_model. And the command line is as follows: phenix.map_to_model_1.12rc0-2787 map_coeffs_file=../rep_dm.mtz map_coeffs_labels="'FP,SIGFP' 'PHIDM' 'FOMDM'" seq_file=../resolve.seq is_crystal=True use_sg_symmetry=True density_select=False truncate_at_d_min=True and the feedback like this: Sorry: No initial assignment made for map_coeffs. Labels used: FP,SIGFP PHIDM FOMDM. Available labels: ['PHIB', 'FOM', 'HLA,HLB,HLC,HLD', 'FP,SIGFP', 'PHIDM', 'FOMDM', 'FDM', 'HLADM,HLBDM,HLCDM,HLDDM'] NOTE: grouped labels like 'FP,SIGFP' must stay together, have commas, and have no spaces. If they come from an MTZ file, they must be in adjacent columns as well. Suggested labels to use: PHIDM FOMDM I try many other input format of map_coeffs_labels, such as map_coeffs_labels="FP,SIGFP PHIDM FOMDM" map_coeffs_labels=["FP,SIGFP PHIDM FOMDM"] ... ... but the result is the same. Dose anyone can tell me how to fix this problem? Thank a lot. -- Wei Ding P.O.Box 603 The Institute of Physics,Chinese Academy of Sciences Beijing,China 100190 Tel: +86-10-82649083 E-mail: dingwei(a)iphy.ac.cn

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Overall anisotropic ADP in phenix.real_space_refine?
by Oliver Clarke 17 Jun '17

17 Jun '17

Hi, I wonder in phenix.real_space_refine whether it may be worth adding refinement of a single overall anisotropic ADP to the model - or a single TLS group with modeled anisotropic ADPs - in order to model the effects of overall orientation errors (which affect resolution more substantially towards the periphery) and preferred orientation (which tends to give rise to anisotropic resolution across the volume). Maybe this would be helpful at least in generating a calculated map that is better for difference map calculation, for example? Cheers Oli

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real_space_refine questions
by Daniel Larsson 14 Jun '17

14 Jun '17

I'm have some questions about doing real space refinements using phenix.real_space_refine. I am refining a model for an intermediate-resolution (3.79 Å) cryo-EM map. As the starting point I use a model from a higher-resolution map (3.25 Å) of the same system in another conformation. My idea is to first do rigid body fitting of domains and then gradually relax constrains and restraints. - Is it possible to restrain the position of certain parts of the model (i.e. "freeze" them so that they move at all) to do focused refinement of subdomains or loops? - In the instructions it says that you can do both NCS constraints and restraints. How you do the latter? I can only do the former by default or by defining ncs_constraints=True and give a NCS definition file. - When I do a run with run=rigid_body, some rigid body groups move in to each other and overlap. Is there no collision detection using this algorithm? If I do a run=minimization_global, things work a bit better in this regard, but is not really what I want (at this stage). Am I doing something wrong? Here is the run command and the rigid body definition file: phenix.real_space_refine \ model.pdb \ map.ccp4 \ rigid.eff \ resolution=8.0 \ ncs_constraints=False \ rotamer_restraints=True \ ramachandran_restraints=True \ c_beta_restraints=True \ run=rigid_body \ macro_cycles=10 # rigid.eff: refinement { rigid_body { group = chain A and resseq 101:266 group = chain A and resseq 273:388 group = chain B and resseq 101:266 group = chain B and resseq 273:388 group = chain C and resseq 104:266 group = chain C and resseq 273:388 } } Regards, Daniel Larsson

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Computational Crystallography Newsletter (CCN) submissions
by Nigel Moriarty 13 Jun '17

13 Jun '17

Folks Calling for articles and short communications of interest to structural biologists. The initial deadline for submission for the July 2017 issue is 30 June 2017. The Computational Crystallography Newsletter (CCN) is an electronic newsletter for structural biologists, and is published online every 6 months. Feature articles, meeting announcements and reports can be submitted to me at any time for consideration. Submission of text by email or word-processing files using the CCN templates is requested. Past newsletters and a Microsoft Word template are available at www.phenix-online.org/newsletter. Cheers Nigel --- Nigel W. Moriarty Building 33R0349, Molecular Biophysics and Integrated Bioimaging 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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