- Chimera-users - RBVI Mailing Lists

Reducing the map to a cubic box
by Sushree Tripathy 15 Apr '15

15 Apr '15

Hi, I went through the chimera user's guide and as per the syntax used "vop boxes #0 #0 useMarkerSize true" or "vop boxes #0 #0 size 36" (the simplest case) to create a cubic box from my density map (54, 36, 51). It is neither giving me any error nor giving me the output map. Please help. Thanks Sushree. Sushree Tripathy Graduate Student Department of Physics University at Buffalo

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generating a map from a atomic model with the same size of its reference map
by 李智海 14 Apr '15

14 Apr '15

hi, here I want to generate a density map from a atomic model in Chimera, then convert the generating map into .pif file to do as the initial map performing in Auto3dem. I have met some questions to successfully finish these work. 1.How can I generate a mol-map from a fitting model with identical dimensions, center coordinates and pixel size of its reference map. I have tried to use “Fit in map”, but the generating map differed from its fitted map in the map size. 2. The mrc map created in Chimera has dimension of even number of columns. If I set the column number to odd number, is it ok (for example, if the origin is off by half pixel?). The reason I am asking such a question is that I will convert this mol-map to pif format, and pif format map has dimension of odd number columns. Thanks in advanced! Best wishes! Zhihai Li

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generating a map from a atomic model with the same size of its reference map
by 李智海 14 Apr '15

14 Apr '15

hi, here I want to generate a density map from a atomic model in Chimera, then convert the generating map into .pif file to do as the initial map performing in Auto3dem. I have met some questions to successfully finish these work. 1.How can I generate a mol-map from a fitting model with identical dimensions, center coordinates and pixel size of its reference map. I have tried to use “Fit in map”, but the generating map differed from its fitted map in the map size. 2. The mrc map created in Chimera has dimension of even number of columns. If I set the column number to odd number, is it ok (for example, if the origin is off by half pixel?). The reason I am asking such a question is that I will convert this mol-map to pif format, and pif format map has dimension of odd number columns. Thanks in advanced! Best wishes! Zhihai Li

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Fitting pdb model into difference map
by Chinaza Egbuta 13 Apr '15

13 Apr '15

I generated an Fo-Fc difference map using CCP4i and was able to superimpose the PDB model structure onto the map in Coot but I am unable to do so with Chimera. The model and map are offset/rotated away from each other and I have not been able to fit the model into the map with Volume Viewer --> Tools --> Fit in Map. Please let me know how I can get around this issue. Thank you. CE

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Extracting masked map region using selected sop piece?
by Oliver Clarke 13 Apr '15

13 Apr '15

Hi all, I find the sop command (particularly 'sop split' and 'sop hideDust metric volume rank') to be very useful for viewing a molecular envelope at a low threshold in an otherwise noisy map. I would like to save the volume enclosed by a single sop piece as a separate volume, but it does not seem like this is possible - when I select a sop piece and use 'volume nameregion’ to assign it a name, and then attempt to write just that region to an mrc, it saves the whole map. Is there some way to do this that I am missing? I realize that a similar outcome can be achieved with segger, but for larger maps this can be very slow (and potentially involve multiple cycles of selection and regrouping), whereas sop operations are almost instantaneous, so I feel it would be a valuable adjunct capability to that offered by segger. Also, the behaviour of sop split seems a little counterintuitive to me. When I use 'sop split' on a volume, it generates a new model with a different ID for the split map - fine so far. However, the original map seems to be completely invisible - it is listed as displayed in the model panel, but if I undisplay the split map in the model panel and toggle display of the original map in the model panel, nothing happens. If I go to the volume viewer, the original map is listed as displayed, and if I toggle it off and then on again there, it reappears. It seems like it would be maybe simpler for the user to just automatically undisplay the original map upon creation of the sop split map, but not to prevent the user from redisplaying it in the model panel. Here is a link to a screen recording demonstrating what I mean: https://www.dropbox.com/s/g40u9dhj0xslcbf/sop_split.mov?dl=0 <https://www.dropbox.com/s/g40u9dhj0xslcbf/sop_split.mov?dl=0> Best, Oliver.

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Fitmap on overlap/correlation only within bounds of smallest map
by Oliver Clarke 13 Apr '15

13 Apr '15

Hi, I am trying to fit a set of large (whole protein) maps to a map corresponding to a single domain of the protein (extracted using ‘vop zone minimalbounds true’ with an atomic model of the domain in question. It works fine, except that it takes rather a long time (~2000 steps), and the final correlation is 0.33, which is strange because the overall correlation between the two complete maps is ~0.95, and I can see that the final overlap between the aligned maps is good. It seems like ‘fitmap’ is calculating the correlation/overlap based on all grid points in the map that I am aligning, which has a much larger box size than the map to which I am aligning it. Is there any way to restrict the metric analysis to just consider points within the smaller box of the reference map? I cannot find such an option in the documentation for fitmap. The use case for this is when one has multiple conformations of a protein (for example, EM volumes after 3D-classsification) and would like to align them on a single reference domain. Best, Oliver.

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Ways to minimize data loss during resampling?
by Oliver Clarke 13 Apr '15

13 Apr '15

When one has multiple maps corresponding to the same protein in different conformations, it is convenient to save aligned copies of each map, for easy comparison later or for transfer to other programs. This requires interpolating the map to be aligned on the grid of the map to which one is aligning, e.g. using “vop resample x ongrid y” in Chimera. This step involves a certain degree of data loss, which is mostly insignificant but occasionally affects the quality of the resultant map in a way that is visually noticeable. Does anyone have any tips for minimizing this data loss, or is that impossible? E.g., if I oversample the map to which I am aligning by lets say 4 times, resample my map on that grid, and then save at gridstep 3 will that help, or is the data loss an unalterable consequence of the interpolation procedure? Best, Oliver.

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Re: [Chimera-users] [chimera-dev] Using Chimera to display family shuffling information.
by Elaine Meng 10 Apr '15

10 Apr '15

On Apr 8, 2015, at 5:11 PM, Matthew Tiffany <matt.tiffany(a)icloud.com> wrote: > To Whom It May Concern: > I am interested in displaying results from DNA shuffling experiments on a crystal structure. Here is a graphical tool that I have found to do this: http://qpmf.rx.umaryland.edu/XoverDemo.html > > What I would like to do is input an alignment of parental sequences and separately a chimeric protein that is derived from the parental sequences by domain shuffling. Then color code a related structure based upon which domain of a parent the chimeric protein came from. The Xover program does this in a graph, but I would like to be able to do this in 3D space. It is similar to color coding by conservation in MultiAlign, but not exactly. Is there any existing plugin that you may be aware of that does this already or a potential backbone plugin that I can use as a starting point to try and code it myself. > > Regards, > Matthew Tiffany > Postdoctoral Fellow > Mark A. Kay Laboratory > Stanford University Hi Matthew, I’ve CC’d the chimera-users list since my answer doesn’t involve programming... Chimera itself includes a lot of sequence-structure interactivity and related features. Certainly you could do it semi-manually: (1) open your 3D structure and sequence alignment in Chimera. You can just the “File… Open” dailog. Chimera understands several sequence alignment formats. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/filetypes.html#alignment> <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/f…> (2) associate the structure with a sequence in the alignment. I don’t know exactly what your data look like, and so this requires some judgment calls and deciding amongst different strategies. My thought is at least initially, don’t worry about which sequence is associated with the structure, just try to get it associated with any sequence so that the 3D mapping along the alignment as a whole is correct. — approach A: just use sequence window menu Structure… Associations to force association with any one of the sequences, if it didn’t already associate automatically — approach B: add the sequence of the chimeric protein to your sequence alignment, sequence window menu Edit… Add Sequence, use From Structure (if it adds it poorly you may have to go through a few cycles of Edit… Delete Sequences/Gaps to remove it and then adding it back with different alignment parameters) … I’m leaning toward approach B as the better approach, but you can see whether one or the other works better for your situation… <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> (3) then you can select the different parts of the structure for coloring by using the mouse in the sequence window to select the appropriate ranges of residues in the structure-associated sequence <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> Another approach to #1-2 above would be to start with a sequence of just your structure (for example, open the structure, use Favorites… Sequence to show its sequence) and Blast against the PDB, then load in the Blast alignment. However, you already have your own alignment so I don’t think it would get you much further. Further, there is a newish “mda” command that performs multiple steps including blasting against PDB, automatically loading in the structures and Blast alignment, and conveniently laying out the structure hits N->C (based on alignment to query) in the 3D display. This also wouldn’t get you much further toward the color mapping of your chimeric structure, but the layout stuff is cool. It might not work if your shuffled cassettes are pretty short though. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/mda.html> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco

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Atomspec balloon don't show up
by LINA MARCELA PEDRAZA CASTILLO 09 Apr '15

09 Apr '15

Hi. (Sorry about my english, it's not my language) Dear users: I'm working on my thesis, and I use Chimera ucsf for everything, and suddenly, one day, it stops showing the atomspec balloons, (when the cursor is paused over an object (atom, bond, surface, *etc.*), whether to show the corresponding label information in a balloon in the graphics window, and PDB chain information, if available, in the status line <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/chimerawindow.html#statusli…>.) OK, That's what's no happening anymore, and I need it, so... Can you help me please with this issue? I already read the docs and I did the modifications at preferences menu, and modify: Labels *Label font* (*Sans Serif* - *Normal -* *16* *Labels on top* (*true* *Show atomspec balloon* (*true* *Atomspec display style* (*simple* Please, help me with this. Thanks. I will appreciate it.

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Mapping predicted secondary structure and solvent accessibility on structure or homology model?
by Oliver Clarke 09 Apr '15

09 Apr '15

Hi, I noticed that in the multalign sequence viewer, Chimera has the option to show predicted secondary structure, but it doesn’t seem to work, at least for my sequence (it seems to work initially, but when I show predicted helices/strands there is nothing to see). I think that incorporating modern secondary structure, solvent accessibility and disorder prediction (e.g. using JPRED, which I believe has an open API) would be a very valuable addition to Chimera for structural analysis - it would be particularly helpful for evaluating homology models and models that are based on low resolution crystallographic or CryoEM data, to pick up places where there might be a register error. Maybe this is something to consider for Chimera 2 (or maybe there is a way to load such data in now, if I could create it externally and load it in as a set of attributes…). Best, Oliver.

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openGL error.
by Mosavverul Hassan 08 Apr '15

08 Apr '15

Hi, I am trying to get chimera run remotely on a linux server while logging into it from a mac terminal. I get the following error libGL error: failed to load driver: swrast X Error of failed request: GLXBadContextTag Major opcode of failed request: 150 (GLX) Minor opcode of failed request: 5 (X_GLXMakeCurrent) Serial number of failed request: 1386 Current serial number in output stream: 1386 glxinfo gives me the following name of display: localhost:13.0 libGL: OpenDriver: trying /usr/lib/x86_64-linux-gnu/dri/tls/swrast_dri.so libGL: OpenDriver: trying /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so libGL: driver does not expose __driDriverGetExtensions_swrast(): /usr/lib/x86_64-linux-gnu/dri/swrast_dri.so: undefined symbol: __driDriverGetExtensions_swrast libGL: Can't open configuration file /mnt/raidc2/mhassan/.drirc: No such file or directory. libGL: Can't open configuration file /mnt/raidc2/mhassan/.drirc: No such file or directory. libGL error: failed to load driver: swrast display: localhost:13 screen: 0 direct rendering: No (If you want to find out why, try setting LIBGL_DEBUG=verbose) server glx vendor string: SGI server glx version string: 1.4 It seems to run fine from a linux computer but has problems with a mac. I am using X11 forwarding when I log in. I have X11 on my mac. Could someone please help me out? Regards, Mosavverul Hassan.

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problems to start chimera
by torquato.bioq＠epm.br 08 Apr '15

08 Apr '15

Dear collegues !! I'm installed chimera-1.10.1-linux_x86_64.bin on my machine witch controlled by openSUSE 13.2. The installation procedure was fine, but when I try start chimera I got this messege: ricardo@ricardolinux:~$ chimera libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast X Error of failed request: GLXBadContextTag Major opcode of failed request: 155 (GLX) Minor opcode of failed request: 5 (X_GLXMakeCurrent) Serial number of failed request: 1457 Current serial number in output stream: 1457 Please can some one help T All the best Ricardo

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plane normal axis
by Elaine Meng 07 Apr '15

07 Apr '15

Hi Oliver, If you have a plane defined in Axes/Planes/Centroids, you can write out its information including the normal (Save button on that tool), then place atoms at either end allowing you to define the axis. There are a few steps... In my little test, the plane output information included: Planes plane name, ID, center, normal, radius plane: p1 ( 19.023, 17.733, 7.080) (-0.380, 0.757, 0.531) 24.199 Then I used Tools… Build Structure, Start Structure, add atom at specific coordinates to add two atoms, one at the center of that plane and one to show the normal. The latter's coordinates are (center + normal) coordinates, and you can multiply the normal coordinates by some constant to make the axis longer. For example, I multiplied the normal coordinates by 10 before adding them to the center coordinates to give the position of the second atom as: x 15.223 y 25.303 z 12.390 Then I selected the two new atoms and used them to define an axis in Axes/Planes/Centroids, see attached image. I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Apr 6, 2015, at 5:01 PM, Oliver Clarke <olibclarke(a)gmail.com> wrote: > Alternatively, would it be possible (or is there some way already) to define a separate axis that is the normal of a plane? In this case I’m working with an ion channel, so I’m looking for a consistent way to represent the change in orientation of particular extramembrane domains with respect to the channel axis. If I could define an axis for the membrane plane normal, I could at least measure the absolute orientation of the principal axes of particular domains or individual helices with respect to the channel axis. It seems like the plane normal is computed already (because there is an option in axes/planes/centroids) to align screen x/y/z to it, but I can’t see a way to generate it as a separate axis that I can use for measuring angles etc. > > Thanks for all your help as always! > > Oliver.

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where is "Save each fit when doing multiple alignments" button
by sunyeping 07 Apr '15

07 Apr '15

Dear all,I am studying the chimera tutorial "fitting to segments" of Segger segmentation tutorials from Greg Pintilie at NCMI (http://ncmi.bcm.edu/ncmi/software/segger/docs_fitting) In the last paragraph, the tutorial states that to align the structure to multiple regions, one needs to check the "Save each fit when doing multiple alignments" button. But where is this button? I cannot find it in the "Fit to Segments", "Segment Map" or other dialogue boxes. Could you tell me where I can find it?Best regard,Yeping Sun Institute of Microbiology, Chinese Academy of Sciences

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how to measure density diameter by chimera
by Smith Liu 07 Apr '15

07 Apr '15

Dear All, Will you please tell me the command or process to measure the diameter of the molecule density in the map by chimera? Smith

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DTI stereo3D
by Dougherty, Matthew T 06 Apr '15

06 Apr '15

?When selecting DTI stereo3D, L&R images are placed side by side, and horizontally rescaled by half, known as SBS-half. I would like to generate SBS-full, ie no horizontal scaling. Is there a way to do that in chimera? Would prefer not to generate stereo pairs and rescale them back to 100% using a video editor. Matthew Dougherty National Center for Macromolecular Imaging Baylor College of Medicine ===========================================================================

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segname
by Francesco Pietra 04 Apr '15

04 Apr '15

Hello: May I ask whether there is till a problem in having CHIMERA understanding segname? For those working with XPLOR (NAMD, for example) and multichain proteins, rendering results with CHIMERA becomes very tedious (having to use atom indexes) Thanks francesco pietra

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Autodock vine problem
by Tunc Morova 04 Apr '15

04 Apr '15

Hello, I was trying to use built-in auto dock vina tool of chimera. I came a cross with an error saying service local`c:\”program filex(x86)”\”the scripps research Institute\Vina\Vina.exe` is unavailable. I have been checking forums for a longtime. Unfortunately, i couldn’t run the docking. couple days ago, I think i accidentally ran the docking locally but i am not sure. Is my pathing correct? how can my local auto dock vina be unavaible ? Please help me for finishing my thesis :D Thank you for your support -Tunc

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Opening Gromacs .trr: error with "bham_lr"
by Alan Manning 03 Apr '15

03 Apr '15

Hi I want to import a Gromacs trajectory (a .trr file) in order to create an animation. I'm using the "MD Movie" tool, and I specify the input .tpr and .trr files. However, I get the following error when I try and make the movie: Don't know correct parameters for 'bham_lr' function Does anyone know what this is from? I'm using Gromacs 5.0.4. The complete Reply Log is as follows: using memory mapping VERSION 5.0.4 using floats version 100, generation 26 2613 atoms box o water Don't know correct parameters for 'bham_lr' function Thanks! Regards, Alan Manning

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drawing ribbon
by Hartzell Jr., Criss 03 Apr '15

03 Apr '15

I have a protein with 10 transmembrane domains and would like to make a movie in which the ribbon is drawn in time from the N- to the C- terminus. I wrote a script that does that. But, the 10 transmembrane domains become hard see because they overlap one another. To solve this problem, I wanted to make the first 600 amino acids become 70% transparent after they had been drawn. Then the drawing would continue with the second half of the protein with no transparency. The problem is that the script that I have written to do this draws the first 600 amino acids 70% transparent immediately as they are drawn. Then the second half of the protein is drawn with 0 transparency. I set the wait time to 600 because I want to execute the transparecny command after the first 600 amino acids were drawn. But, instead, the drawing of the first 600 amino acids is tremendously slowed down by this command as if a wait of some duration occurs after each amino acid rather than after all 600 amino acids. I would appreciate your help. Thanks. movie record supersample 4; perframe "ribbon #2:$1" range 1,600; wait 600; transparency 70,r #2:1-600; perframe "ribbon #2:$1" range 601,959; movie stop; movie encode “d:\Dropbox\Chimera_files\movie1.mp4”; Criss Hartzell Professor Department of Cell Biology Emory University School of Medicine Atlanta, GA 30322 404-242-5719 (cell) For Fedex, UPS, other courier: Criss Hartzell 615 Michael St. 535 Whitehead Building Emory University Atlanta, GA 30322 ________________________________ This e-mail message (including any attachments) is for the sole use of the intended recipient(s) and may contain confidential and privileged information. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this message (including any attachments) is strictly prohibited. If you have received this message in error, please contact the sender by reply e-mail message and destroy all copies of the original message (including attachments).

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New molecule from selection?
by Oliver Clarke 03 Apr '15

03 Apr '15

Hi, This may already be implemented, but I couldn’t find it - the nearest equivalent feature I know of is copy/combine, but that only works on whole models, not taking into account selections. I was wondering if it would be possible to implement a feature creating a new model comprised of all atoms in the current selection? This would be particularly helpful when combining many parts of multiple models, or when creating a separate model consisting of a subselection of the current model. This can be done at present using a combination of copy/combine and selecting and deleting those parts of the copied molecules that are not in the selection, but this gets messy for complicated selections. Best, Oliver.

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select by color (or other display attributes)
by Oliver Clarke 02 Apr '15

02 Apr '15

Hi, one feature I would love to see in a future version of chimera is the capacity to select residues/atoms by color - this would be magic for modifying figures. Example use case: I’ve made a figure in which some complicated selection or set of selections is colored medium blue, and another selection is colored red. I’ve saved the session for the figure, but I (stupidly)didn’t save the corresponding selections, and now I have to remember exactly what selections I used. If there was a “select by color” function, I could simply select all the atoms that are colored medium blue (or some other color ID), and change them to another color, without having to know which residues were in the original selection. Analagously, it would also be handy, although less frequently useful, to be able to select on the basis of whether a residue is displayed, or represented in a particular manner - in particular, being able to restrict selection to displayed atoms/residues would be useful to avoid inadvertent modification of undisplayed models or parts thereof. Cheers, Oliver.

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Smoothly change level of density map in animation?
by Oliver Clarke 02 Apr '15

02 Apr '15

Is there any way to alter the density level in a gradual fashion during an animation? I would like to first show the overall envelope of a cryoEM map, and then smoothly change to a higher contour level where I can see helices etc. Many other parameters, such as the presence of a MSMS surface or the position of a clipping plane, seem to automatically gradually transition between two key frames of an animation, but density level doesn’t seem to do so. Oliver.

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mclip suggestion - match to arbitrary plane
by Oliver Clarke 01 Apr '15

01 Apr '15

Hi, Currently the mclip command can be used to match a model specific clipping plane to the global near/far clipping planes, or the per model clipping plane of another model. I think it would be a handy addition to a future chimera version to be able to match the per model clipping plane to an arbitrary plane, pre-defined in axes/planes/centroids - e.g. “mclip #1 match p2” would match the per model clipping plane of model #1 to the plane named “p2”. This would be useful because it allows one to easily generate a per-model clipping plane that intersects a certain set of atoms, which also facilitates precise description of a figure. Cheers, Oliver.

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Request for axes measurements
by Jayaraman T 31 Mar '15

31 Mar '15

Hi, I'm Jayaraman, pursuing PhD in Protein Engineering at Pusan National University. I just want to calculate the Axes for specific set of helical residue CA atoms and then to calculate the angle between them. Is it possible with Chimera and if so, please do help me out that how to do it. It would be grateful and looking forward to hear at your earliest convenience. Thank you. - - With warm regards Jram | 201493155 PhD Scholar jram(a)pusan.ac.kr Bio molecular Engineering Lab Dept of Chemical Engineering Pusan National University Busan, South Korea +8210 9906 3680

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