- Chimera-users - RBVI Mailing Lists

MMTK/Chimera interface error
by ADIL AHIRI 27 Feb '17

27 Feb '17

hi everyone, I work on the modeling of the effect of phosphorylation on segment peptide. I had a problem when i use this interface MMTK/Chimera interface because when i use a doubly phosphorylated peptide i have this message: KeyError: 'No parameters for bond Atom 0.ARG_12__0_0_1_286__B.peptide.C (atom type C) - Atom 0.TPO_13__0_0_1_287__B.N (atom type n)' You will find attached a sample problem source file. Is there anyone who can help me solve this problem please. Codially

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coloring a surface based on proximity to a point
by Hamish Todd 27 Feb '17

27 Feb '17

Hey everyone. So I have a coloration for a set of surfaces that is very close to what I want. I want to make a change to it though: I want parts of the surfaces close to certain points to change their color. And I want the rest of the surface to be unchanged from the current coloring. Is this possible? Would be much obliged if any advice could be offered! Hamish Todd -- @hamish_todd

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starting pre-existing morph
by Elena Zehr 27 Feb '17

27 Feb '17

Hi, I have a chimera session with a morph between two structures. I wish to start playing the morph from the command line. What would be the argument for this? Many thanks, Elena

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FW: Commercial Chimera
by Williams, Joanne 27 Feb '17

27 Feb '17

On 2/26/17, 10:29 PM, "Agnieszka Dobinska" <adobinska(a)okinawa-pt.com> wrote: >Dear Sir/Ma'am, > >I have a questions regarding commercial use of Chimera. > >Provided that we are commercial users of Chimera (subject to commercial >agreement), and we are creating files using Chimera, does our customers >need to >have the commercial Chimera to browse the files we have sent them, or >they can >use the free one. > >Best regards, >Agnieszka Dobinska > >~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~ >Agnieszka Dobinska >Sales & Marketing Manager >Okinawa Protein Tomography Ltd. >1919-1 Tancha, Onna Village, Kunigami, >Okinawa Prefecture 904-0411 Japan >Tel. +81-98-982-3359 　FAX +81-98-982-3361 >Skype: okpt.sales >http://www.okinawa-pt.com >~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~ > > >

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models disappear after using "split"
by Leschziner, Andres 24 Feb '17

24 Feb '17

Hi, I used “split” to break a model into its 19 component chains. The chains appear in the Model Panel and are marked as “Shown" but are gone from the display. Everything else I have in the session works normally but nothing I have tried so far makes the split models show up. Any help solving this would be much appreciated! -Andres ______________________________________ Andres Leschziner Professor Department of Cellular and Molecular Medicine and Section of Molecular Biology, Division of Biological Sciences University of California, San Diego Leichtag 483 9500 Gilman Dr. La Jolla, CA 92093-0694 aleschziner(a)ucsd.edu<mailto:aleschziner@ucsd.edu> 858-246-1252 ______________________________________

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density maps
by Antonio Coluccia 24 Feb '17

24 Feb '17

Dear all I have computed a molecular dynamic and i would like to have the density maps for some molecules of the system. I tried with isopropanol molecules and I obtain the map for each atom type: H; C3; O3, CH and another called density map_iso.mcr My concerns are about the last one map. What does it mean? Is it the map for the whole molecules, while the other maps are for each atom type? Is it possible to analyse the maps contemporary thus I am able to visualize just three per time? Any help will be really appreciated. Antonio Antonio Coluccia Ph.D. Department of Chemistry and Drugs Technology Rome 00185 Piazzale Aldo Moro 5 antonio.coluccia(a)uniroma1.it

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Two questions about a model
by Steven D. Aird 23 Feb '17

23 Feb '17

Dear Elaine, I have a couple of questions about the attached model set. These are catalytic residues and residues forming the hydrophobic channel in four phospholipases. The first question almost seems silly. I decided to experiment with the label command and labeled one residue in the lower right enzyme of the figure. I didn’t like the position or form of the label. I couldn’t get rid of the “.A” on the label and when I tried to delete the entire label, I couldn’t. Selecting the residue and then selecting LABEL>Off, doesn’t work. In all four plots there are fine lines that resemble the earlier ribspline problem, but they are not resolved by "ribspline cardinal.” Any idea as to what these are? As always, thank you for your tutelage. I am making steady progress. Sincerely yours, Steve Steven D. Aird Technical Editor Faculty Affairs Division Okinawa Institute of Science and Technology Graduate University 1919-1 Tancha, Onna-son Kunigami-gun, Okinawa-ken Japan 904-0495 Phone: 098-982-3584 Cell: 080-4154-9504 Email: steven.aird(a)oist.jp

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Windows & dialogues outside the screen
by Hernando J Sosa 22 Feb '17

22 Feb '17

Dear UCSF-Chimera, I have noticed (perhaps since I upgraded, currently running v1.11.2) that when opening new windows/dialogues many times they pop-up outside the screen. This seems to happen more often when many windows are opened simultaneously. It is more of a nuisance than a real problem but it can get annoying having to continuously search for those elusive windows. So I wonder if there is a way to fix this behavior (e.g. to force newly opened windows to always appear on top and within the screen boundaries) . I am running Windows 64 UCSF-Chimera version 1.11.2 on a Windows 7 and Windows 10 machine (problem occurs in both computers) Thanks Hernando

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Converting a part of a molecule in pdb to xyz format
by Vladyslav Dziuba 22 Feb '17

22 Feb '17

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Re: [Chimera-users] MatchMaker working beautifully, and Transform Coordinates definitely does move things....
by Elaine Meng 17 Feb '17

17 Feb '17

> On Feb 17, 2017, at 3:47 AM, Steven D. Aird <steven.d.aird(a)gmail.com> wrote: > > Dear Elaine, > I apologize for the deluge of Email, but within minutes of writing you, I figured out how to use MatchMaker to align two ribbon models of interest. Again, it’s simple and elegant. > > I also found the transform coordinates command, which I had missed earlier. That enables me to move one of the models relative to the other. But moving a model is tricky because it seems impossible to know what relationship the two models have with a Cartesian coordinate system. I had assumed that x, y, and z would be relative to the monitor surface, but that is not the case. > > Is there a more intuitive way to move molecules while maintaining the same relative orientation? > Thanks very much for your help. > Sincerely yours, > Steve Hi Steve, Thanks for the kind words! After you use Matchmaker (or matrixcopy or the mouse or some other method) to position structures relative to one another, you shouldn’t have to do anything special… now when you move “everything” they will still retain their relationships. I.e. you can rotate and translate everything with the mouse and structures will still be superimposed, docked, etc. as they were after you moved them separately. Personally I never use the Transform Coordinates tool and I don’t understand why you wanted to use it. You can translate and rotate relative to screen coordinates (X horizontal Y vertical Z normal to screen) using commands “move” and “turn” and these can apply to everything or only certain models (they have a “models” keyword option). You can also move only certain models with the mouse by activating/deactivating (freezing) them with the “A” checkboxes in the Model Panel, which can be opened from the Favorites menu. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/mouse.html#activedef> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/move.html> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/turn.html> Also, for future reference, we really prefer questions to be sent to chimera-users (CC’d here) so that other people can benefit from the answers, and also give you better support if I don’t know the answer or am away. 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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Chimera refuses to attach short peptide to protein C-terminus
by Steven Douglas Aird 16 Feb '17

16 Feb '17

Dear Sirs: I am modeling novel proteins on homologous structures from other organisms using SWISS-MODEL. After the model is completed I import the PDB file into Chimera to form disulfides and to produce publication quality graphics. I thought all was going well until I discovered that SWISS-MODEL was actually truncating one or both termini of my target sequences by 1-5 residues. In one case, I created the missing C-terminal tripeptide using MacPyMol, but MacPyMol will not not add the tripeptide to the C-terminus, because it is designed only to create intramolecular bonds. So I imported the protein and the tripeptide into Chimera. I selected the C-terminal oxygen of the protein and the N-terminal nitrogen of the tripeptide and tried to create a peptide bond using Build Structure>Adjust Bonds>Add Bond. Chimera claims that only one atom is selected, but in fact, both are selected. I do not want to try to build a tripeptide one atom at a time. Is there any way to do ligate the tripeptide? Thanks very much! Steve Aird Steven D. Aird Technical Editor Faculty Affairs Division Okinawa Institute of Science and Technology Graduate University 1919-1 Tancha, Onna-son Kunigami-gun, Okinawa-ken Japan 904-0495 Phone: 098-982-3584 Cell: 080-4154-9504 Email: steven.aird(a)oist.jp<mailto:steven.aird@oist.jp>

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Visualisation of membrane proteins
by James Starlight 15 Feb '17

15 Feb '17

Dear Chimera users! I am on the preparation of interactive molecular visualisation, focusing on ligand-binding representation in GPCRs system. Working with the X-ray structures of the receptor bound with the ligand, I wonder to ask some suggestions: 1 - I need to move ligand from ligand binding pocket burried within receptor (as on default in the X-ray structure) towards the selected position outside of it - e.g in case where I would like to depict "vestibule" for the ligand enterance. As I understood for the realisation I should to select ligand within the current model and than to copy it to new model (layer) which then should be moved against the structure, shouldn't it? 2- Is it possible using some Chimera tool to indicate "approximate" membrane plane assuming that GPCRs structure is shown in latteral perspective? Thanks so much for the help! James

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electrostatic surface
by chemocev marker 13 Feb '17

13 Feb '17

Hi I am calculating the electrostatic surface of the protein that has a peptide bound inside the catalytic camber. There are two ways to calculate, either i can split the molecule in indivual chain and calculate their surface indivdually and run the APBS server for the electrostatic potential, or i can do it use the surfcat command. Both of them works but the results are different. To me the results are more logical by splitting the molecule in indivual chain, but u am not sure if its right to do that specially when you want to measure the electrostatic potential. What is your opinion. best Jiri

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Write out coordinates for Centre of mass
by Soumya Govinda Remesh 10 Feb '17

10 Feb '17

Hello, I wanted to know if I can write out the coordinates for the object placed at the 'centre of mass' of selected atoms from a domain. I used the following command to place a marker at the location of interest. - measure center sel mark true Thanks Best, Soumya Govinda Remesh, Ph.D. Postdoctoral Fellow at Advanced Light Source Lawrence Berkeley National Laboratory 1 Cyclotron Road MS 6R2100 Berkeley, CA 94720 (phone) 510-495-8179 (cell) 804-402-8730 sgremesh(a)lbl.gov

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Re: [Chimera-users] CHIMERA ERROR
by Eric Pettersen 10 Feb '17

10 Feb '17

> On Feb 8, 2017, at 9:07 AM, Stellamaris Sotomayor Burneo <stellamaris_sb(a)yahoo.com> wrote: > > > Dear Dr. Eric, > > My name is Stellamaris. I am an undergraduate student from Ecuador. There is almost no one working in molecular docking in my country so far. So, it is very difficult to find somebody to ask for help. I would like to kindly ask you a question about the problem I am having with Chimera and I would really appreciate your help. > > I am trying to convert a set of receptors (named receptor.pdb) to receptor.mol2. using chimera. However i am having problems with the charges of FAD, NAD, NDP, and FMN. Receptors that have problems in those groups are not being transformed. > > Is there a way to transform those files without having to change to charges? I have tried changing the charges and it seems to work. However, I am very afraid of changing the conditions of my simulations if I change the charges. > > I have gotten the following message: > NAD) Error: cannot run "/opt/UCSF/Chimera64-1.10.2/bin/amber14/bin/sqm -O -i sqm.in -o sqm.out" of bcc() in charge.c properly, exit > Failure running ANTECHAMBER for residue NAD Hi Stellamaris, As you have discovered, the underlying tools that Chimera relies on to derive charges (AmberTools/antechamber/sqm) sometimes fail for entities with concentrated areas of negative charge. It is for this reason that Chimera already includes pre-calculated charges for ADP, ATP, GDP, and GTP. These charges were taken from the AMBER parameter database <http://research.bmh.manchester.ac.uk/bryce/amber>. Charges for the moieties you mentioned are also in that database, and I’ve gone ahead and added NAD and NDP to the ones that Chimera knows about without needing to do a calculation. Precalculated NAD/NDP charges will be available in daily builds dated Feb. 9 or later. Unfortunately, FMN and FAD are more problematic in that Chimera doesn’t protonate them in the standard way used in the database. It adds a proton (and positive charge) to the isoalloxazine ring system so that the central ring becomes aromatic. Obviously, the simplest way to deal with this if you don’t need FAD/FMN as a cofactor is to simply delete them. If you do need them then things get hairy. I guess what I would do is: 1) Delete FMN/FAD. 2) Run Dock Prep which will get you a Mol2 file of the remainder of the system with charges. 3) Close your system and reopen it. 4) Delete everything but the FMN/FAD. 5) Set the IDATM types of the FMN/FAD so that they correspond to the standard protonation pattern. 6) Add hydrogens. 7) Write another Mol2 file with just FMN/FAD. 8) Edit this second Mol2 file and transcribe the charges found in the corresponding Amber parameter database file to the atoms. 9) Combine your two Mol2 files. Step 6 is a little tricky in that the atom names in the “OFF” parameter files aren’t all the same as the PDB standard names, but there is connectivity information in the OFF file, so you can figure out which atom is which. You can do step 5 by running the “defattr” command with the file I have attached, which will set the types of FMN/FAD heavy atoms to the standard protonation pattern. Also, instead of step 8, you could work up another “defattr” file to assign charges to the FMN/FAD before you write out the Mol2 file. Probably easier. —Eric Eric Pettersen UCSF Computer Graphics Lab

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large structures and two letter chain IDs
by Petr Leiman 09 Feb '17

09 Feb '17

Dear Chimera Users and Developers, I am writing to ask if there is a way to animate multiple conformations of a structure containing 144 chains (~300,000 atoms)? Is it possible to read in such a structure into Chimera and preserve chain IDs? We have to use two-letter chain IDs, something that Chimera does not seem to like. Thank you, Petr -------------- Petr Leiman UTMB Galveston, TX77555

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Re: [Chimera-users] Fwd: chimera MAV
by Elaine Meng 09 Feb '17

09 Feb '17

Hi Jackie, Yes, see the sequence window menu: "Preferences… Appearance. " There are several options for spacing, font, and coloring, including “Space between wrapped blocks.” <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> Best, Elaine > On Feb 9, 2017, at 12:45 AM, Jacqueline Vitali <jackie.vitali(a)gmail.com> wrote: > > Elaine, > > Thank you so much. Doing it by hand is the easiest. > Also, is there a way to increase the distance between wrapped blocks? > > Jackie Vitali > Cleveland State University > > On Wed, Feb 8, 2017 at 1:39 PM, Elaine Meng <meng(a)cgl.ucsf.edu> wrote: > You can also: > > (1) hide/show the header lines (Conservation, Consensus, etc.) using the sequence window Headers menu > (2) change how Conservation is calculated (sequence window Preferences… Headers) > (3) add your own headers with quantities or symbols, e.g. put stars over the columns with superfamily-conserved residues > > <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> > > Elaine > > > On Feb 8, 2017, at 8:30 AM, Elaine Meng <meng(a)cgl.ucsf.edu> wrote: > > > > Hi Jackie, > > You can draw boxes (we call them “regions”) in the alignment wherever you want with click and drag, and then change their colors using the Region Browser. > > > > Multalign Viewer: > > <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/f…> > > > > Regions, including how to create them manually: > > <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> > > > > Region Browser (click the square color wells to change colors): > > <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> > > > > I hope this helps, > > Elaine > > > > > >> On Feb 7, 2017, at 10:57 PM, Jacqueline Vitali <jackie.vitali(a)gmail.com> wrote: > >> > >> Elaine, > >> > >> I would appreciate it very much if you could let me know how to highlight specific conserved residues in a sequence alignment between 2 proteins with chimera using the MAV? I highlight helices and beta sheets with colors, conservation between the 2 proteins is shown with the blocks on top. But there are 15-20 residues conserved in the superfamily of proteins and i would like to use blocks around them or highlight them in different color. In other words, 60 residues are conserved between the 2 proteins and 20 are special and need to be shown in a different way. > >> > >> I hope my question is clear. > >> > >> Thank you in advance. > >> > >> Jackie Vitali > >> Cleveland State University > >

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Re: [Chimera-users] Fwd: chimera MAV
by Elaine Meng 08 Feb '17

08 Feb '17

Hi Jackie, You can draw boxes (we call them “regions”) in the alignment wherever you want with click and drag, and then change their colors using the Region Browser. Multalign Viewer: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/f…> Regions, including how to create them manually: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> Region Browser (click the square color wells to change colors): <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/multalignviewer/m…> 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 Feb 7, 2017, at 10:57 PM, Jacqueline Vitali <jackie.vitali(a)gmail.com> wrote: > > Elaine, > > I would appreciate it very much if you could let me know how to highlight specific conserved residues in a sequence alignment between 2 proteins with chimera using the MAV? I highlight helices and beta sheets with colors, conservation between the 2 proteins is shown with the blocks on top. But there are 15-20 residues conserved in the superfamily of proteins and i would like to use blocks around them or highlight them in different color. In other words, 60 residues are conserved between the 2 proteins and 20 are special and need to be shown in a different way. > > I hope my question is clear. > > Thank you in advance. > > Jackie Vitali > Cleveland State University >

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Re: [Chimera-users] Upgrade to Sierra
by Elaine Meng 06 Feb '17

06 Feb '17

> -------- Forwarded Message -------- > Subject: Upgrade to Sierra > Date: Sun, 5 Feb 2017 17:58:53 +0100 > From: F.Xavier Gomis-Rüth <fxgr(a)ibmb.csic.es> > > Dear Elaine, > I recently had to upgrade to Sierra from Mountain Lion and now I find that ions are displayed as black spheres only > in Chimera v. 1.9. Any ideas on what I should change? > Kind regards, > Xavier > On Feb 5, 2017, at 9:11 AM, F.Xavier Gomis-Rüth <fxgr(a)ibmb.csic.es> wrote: > > Elaine, it's not only the ions, its all the atoms and bonds. > Ribbon appear fine though.... > Dear Xavier, I’m not an expert on this kind of thing, so I’m forwarding to the chimera-users list. (Sending to the list is always recommended… I will still answer it if I can, just as fast!) Although I don’t know if it’s related, maybe you should get a newer version of Chimera. Using Chimera versions 1.11.2 and 1.12 daily build on both a laptop and a desktop running Sierra, I do not have this problem. Best, 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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Re: [Chimera-users] Contour level animation ?
by Elaine Meng 04 Feb '17

04 Feb '17

> On Feb 3, 2017, at 4:21 PM, esserlo(a)helix.nih.gov wrote: > > Hi Elaine, > for a small demonstration, I want to make a movie in chimera where I animate > a change in contour level. I have an EM map with noisy features that improve > upon changing the level. I can do it by hand in the volume section but I > cannot figure out what parameter it is even if I wanted to set it on the > command line. > Setting it on the command line I suppose would be the first step but then my > question is: can this parameter be changed during an animation? > Thanks, > Lothar Hi Lothar, Yes, you can use the “volume” command “level” option to change the contour level. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/volume.html> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/volume.html#general> The “volume” command doesn’t itself have frames option, but you can combine it with the “perframe” command to perform a gradual change in a single line, as illustrated with this video mini-example: <http://www.cgl.ucsf.edu/chimera/data/movie-howto-mar2012/movie_examples.htm…> We generally encourage emailing questions to chimera-users (CC’d here) unless they involve private data, since others may like to know the answer. 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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Re: [Chimera-users] [chimera-dev] (no subject)
by Tom Goddard 02 Feb '17

02 Feb '17

Hi Kavya, How about just measuring the distance between the two monomer center of mass points of the homodimer and dividing that distance by 2 since the line between the two monomers will intersect the symmetry axis in the middle. For example for monomer chains A and B "measure center :.A ; measure center :.B ; distance #1,2”. Send this type of question to chimera-users instead of the chimera-dev list which is for developer programming questions. Tom > On Feb 2, 2017, at 1:39 PM, Kavya Shankar wrote: > > Hi, > > Is it possible to find the distance between a point and a line in chimera? I am trying to find the distance from the center of mass of the protein to the 2 fold axis of the homodimer. > > Thanks. > > Regards, > Kavya > _______________________________________________ > Chimera-dev mailing list > Chimera-dev(a)cgl.ucsf.edu > http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-dev

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3D movies for projects
by Kenward Vaughan 02 Feb '17

02 Feb '17

Hello, I'm developing a project for my class which feels like it's taking on Chimera (as in the creature) like proportions for the students. The thought is to have presentations of their visualization studies presented in a conference like setting at our school, open to all students. The question that has pounced into my thoughts is the possibility of using some settings within Chimera allowing them to record a movie (even as simple as a screen capture) which can then be played using an Oculus headset (or similar) with a phone. This would be a simple way to get the technology out into the street, so to speak. I do not yet have one of these myself so really don't know this first hand, but thought using wall-eye stereo made sense...?? Has anyone tried this, hopefully successfully? Kenward ps. Is there a way to use the phone as a monitor so one can manipulate the images via an external device, or use a Bluetooth hand controller? (I expect this is not possible given the graphics constraints of phones...) -- In a completely rational society, the best of us would aspire to be _teachers_ and the rest of us would have to settle for something less, because passing civilization along from one generation to the next ought to be the highest honor and the highest responsibility anyone could have. - Lee Iacocca

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Help with coordinates please
by drew richardson 01 Feb '17

01 Feb '17

Hi, I am very new chimera and I am having to use it for a project at university. I have to create a picture from chimera and then list commands so anybody can recreate it just by typing in the commands in the command box. The problem I am having is: once I have rotated and zoomed manually using the mouse I don't know how to recreate that position and view by using typed commands. I can't even seem to find anywhere the coordinates of the new rotation. Could you please help me? How do I recreate the zoom and rotation using commands only, so that anyone wanting to recreate the view I have can do it just by typing in a list of commands after loading my original PDB file? Kind regards Drew Richardson ID: 27927431 (1st year biochemistry)

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Help!
by Kempfer, Jamie E. 31 Jan '17

31 Jan '17

i cannot get chimera to work on my windows computer!

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Re: [Chimera-users] on chimera unit cell function
by Elaine Meng 31 Jan '17

31 Jan '17

Hi Smith, The Unit Cell results for a structure with and without “pack” are equivalent because the symmetry describes a repeating pattern: each single copy could be shown in any of several places around the first copy. In other words, as I said before, there are multiple equally correct ways of presenting the same information. Although I cannot spend a lot of time looking at your specific data, I see the 3 structures are all the same space group with similar unit cell dimensions and angles, and the paper says “we could present nucleotide-induced conformational changes in the same crystal lattice by eliminating possible artificial structural differences because of different crystal packing.” Therefore I infer that the crystal packing is approximately the same in the 3 structures. It cannot be EXACTLY the same, however, since there are conformational changes between the structures. Since I didn’t write the Unit Cell code or look at the symmetry matrices in detail, I don’t know why the structures don’t give the same arrangement without “pack,” but I don’t think it is important, since the different possible arrangements for a single structure are equally correct. I hope this helps, Elaine P.S. please send questions to chimera-users rather than to me individually - thanks > Begin forwarded message: > > From: "Smith Liu" <smith_liu123(a)163.com> > Subject: Fw:Re: [Chimera-users] on chimera unit cell function > Date: January 31, 2017 at 7:01:54 AM PST > To: meng(a)cgl.ucsf.edu > > Dear Elaine, > > Related to our previous communication on "on chimera unit cell function" , here I have more to discuss with you. > > Attached 1 was the paper “Nucleotide-Dependent Conformational Changes and > Assembly of the AAA ATPase SKD1/VPS4B” published in Traffic 2008. PDB ID 2ZAM, 2ZAN, 2ZAO were 3 pdbs from this paper, and 2ZAM was the VPS4B without any nucleotide, 2ZAN was the VPS4B bound with ATP, 2ZAO as the VPS4B bound with ADP. > > As the paper wrote, “Because our attempts to crystallize SKD1 (VPS4B) in the presence > of ATP or ADP failed, we soaked the apo form crystals in solutions of ATP or ADP”, thus the 2ZAN and 2ZAO were got by soaking the crystal for 2ZAM with ATP and ADP separately. All 3 crystals were with space group P 65. > > The pdb for the 6 mates for each of 2ZAM, 2ZAN and 2ZAO are attached in attachment 2, 3, 4 separately (prepared without clicking ""Pack molecules in unit cell"). If viewed by Chimera, you will find the mates of 2ZAM arrange in the same way as the mates of 2ZAO, i.e., the 6 mates connect each other closely (side by side) and packed in a screw way. However for the 6 mates of 2ZAN, although still in screw way, the 6 mates arrange not closely but have a space between the adjacent mates. Correspondingly, the diameters of the z-axis projection of the 6 mates of 2ZAM and 2ZAO were much smaller than that of the 6 mates of 2ZAN. > > However, if we by Chimera we click the "Pack molecules in unit cell",we will find the 6 mates of 2ZAN displayed exactly (or very similarly) as the 6 mates of 2ZAM and 2ZAO (Am I right). > > Then my question would be, in the crystal for 2ZAN and 2ZAO, do the proteins arranged in exactly the same pattern? And why if we did not click ""Pack molecules in unit cell", the mates of 2ZAN and 2ZAO were displayed differently, and with clicking ""Pack molecules in unit cell",the mates of 2ZAN and 2ZAO were displayed similarly? > > If the protein arranged differently in the crystal for 2ZAN and 2ZAO, then in the crystal packing of 2ZAN, how can I identify the 6 protein which were from the 6 screwed mates in 2ZAM? > > I am looking forward to getting a reply from you. > Smith > -------- Forwarding messages -------- > From: "Elaine Meng" <meng(a)cgl.ucsf.edu> > Date: 2017-01-30 04:05:22 > To: "Smith Liu" <smith_liu123(a)163.com> > Cc: "chimera-users(a)cgl.ucsf.edu BB" <chimera-users(a)cgl.ucsf.edu> > Subject: Re: [Chimera-users] on chimera unit cell function > Hi Smith, > The number of copies and their positions are all correct no matter whether you choose the “pack” option or not. If you cut out a part of the real crystal, there will be a real copy in the same place as the copy from Chimera. So imagine if you had specified an infinite (or large) number of unit cells in Chimera, a chunk from the middle of the result would look the same as some chunk of the real idealized crystal, regardless of whether you used “pack”. However, since you are probably specifying 1 x 1 x 1 or some small number of unit cells, yes choose the “pack” option to show the copies packed together, instead of with some spaces where a copy is shown inside a neighboring box rather than in the central outline box. > Best, > Elaine > > > On Jan 29, 2017, at 5:10 AM, Smith Liu <smith_liu123(a)163.com> wrote: > > > > Dear Elaine, > > > > I am still confusing on the function of "Pack molecules in unit cell" in Chimera. If we cut out a cube (or a volume) of crystal based on which a pdb was got, do you think the molecules packed in the cube in the way without "Pack molecules in unit cell" clicked, or the molecules packed in the cube in the way with "Pack molecules in unit cell" clicked? > > > > I am looking forward to getting a reply from you. > > > > Smith > > > > > > At 2017-01-29 00:50:44, "Elaine Meng" <meng(a)cgl.ucsf.edu> wrote: > > >Hi Smith, > > >It is my understanding that you will get the same number of copies whether or not you choose the “pack” option, and that there are multiple equally correct ways in which the copies will be positioned according to the symmetry information. The “pack” option simply chooses, out of these many equally correct alternatives, a configuration that places the centers of all the copies inside one unit cell outline box instead of spreading them out among neighboring boxes. > > >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 Jan 28, 2017, at 1:47 AM, Smith Liu <smith_liu123(a)163.com> wrote: > > >> > > >> Dear All, > > >> > > >> In Chimera, we do Tools →Higher-Order Structure→Unit Cell, then what will be the diffenrence if we clicked "Pack molecules in unit cell" in comparison with if we did not click "Pack molecules in unit cell"? Does it mean that what we observed (or what Chimera displayed) if we click "Pack molecules in unit cell" , was really part of what it displayed if we did not click "Pack molecules in unit cell" but we increased the "Number of Cells" significantly? > > >> > > >> I am looking forward to getting a reply from you. > > >> > > >> Smith >

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