- Chimera-users - RBVI Mailing Lists

fitting antibody and envelope protein structures to EM map of virus: C3 and icosahedral symmetries
by Kent, Michael S 02 Jan '19

02 Jan '19

I have an EM map for a virus that includes an antibody bound to the envelope proteins. The envelope proteins are trimers of dimers with C3 symmetry that form spikes on the surface of the virus. I fit an atomic model for the spikes to the map using icosahedral symmetry, following the very helpful symmetric fitting video tutorial<http://www.cgl.ucsf.edu/chimera/videodoc/SymFitDNAb/>. Now I am trying to fit a model for the antibody into the spike regions of the map. I need to impose C3 symmetry for the antibody for the fit into each spike, in addition to imposing icosahedral symmetry to include all the spikes. How can I impose both of these in the fit? Thanks, ?Mike Kent

2 1

MD animation of electrostatic map
by Bala subramanian 02 Jan '19

02 Jan '19

Dear Chimera users, I have a series of structures (tens of snapshots from MD) for which i have calculated the electrostatic potential (with APBS). I would like to know if there is any way,for instance using MD-movie plugin, to map the elect. potential corresponding to each structure so that i can actually visualize the changes in surface potential. All structures have been already fitted to a reference structure, hence there wnt be any rotation or translation. Any idea or trick to achieve such mapping would be greatly appreciated. Thanks, Bala -- C. Balasubramanian

2 1

Adding Heme ligand to protein pdb
by Yangqi Gu 01 Jan '19

01 Jan '19

Dear Chimera users, I have a pdb file of my protein, but not showing the binding ligand (Heme). I know where the binding motif is and I am wondering is there a way I can add ligand to the binding motif and write out the new pdb file in Chimera? Best, Yangqi -- Yangqi Gu Graduate Student Malvankar Lab Yale University, West Campus

3 8

H bonds
by kloe brathon 31 Dec '18

31 Dec '18

Dear Chimera users, I want to calculate H bonds between the ligand of my protein and its nearby residues. Could you give any suggestions on how to select this residues and calculate H bonds between them and the ligand? Kind regards,Kloe

2 3

Visualizing SwissDock clusters.dock4.pdb
by Francesco Pietra 31 Dec '18

31 Dec '18

Hi all I am trying to open sequentially with chimera the various clusters generated by SwissDock (file clusters.dock4.pdb in the output). I was only able to extract clusters from clusters.dock4.pdb and view them, one by one, with chimera. Or a way to highlight the varius pdbs from loading clusters.dock4.pdb and target.pdb, in order to see where they are located. The web gui by SwissDock was much too grob. Thanks for advice francesco pietra

2 1

Re: [Chimera-users] Help on removing ligand on a pdb file with protein in complex with ligand and viewing the conformational change
by Elaine Meng 26 Dec '18

26 Dec '18

Dear Kei Onn, When you open the structure in Chimera, the conformers are already separate submodels, and it looks like they are already superimposed. Also you can delete the ligand residue in all submodels at the same time using the ligand residue name, which is “PKA” according to the the information for this structure at the RCSB PDB: <http://www.rcsb.org/structure/2MGY> I.e.Chimera command: delete :pka However, you need to consider what makes scientific sense. If you just delete the ligand, Chimera is not going to predict the change in the rest of the structure, so it will just look exactly the same as it did before except without ligand. Instead you should search the PDB for a structure of the same or similar (e.g. homolog in different species) protein that has been solved without the ligand. Then you would actually have something different to compare to the structure(s)with the ligand. One way to search is with Blast Protein in the Chimera menu under Tools… Sequence. You have to look through the results and figure out which ones do and don’t have ligand. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/blast.html> I’m sure there are other ways to look for related structures, so you could certainly use other programs or websites to do that. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco > On Dec 24, 2018, at 6:55 PM, #LAI KEI ONN# <KEIONN001(a)e.ntu.edu.sg> wrote: > > Dear Elaine, Eric, Chimera Team and fellow users > > Thank you very much for the great work in developing Chimera! > I was wondering if there's a way in Chimera for me to visualise my protein of interest without the ligand bound to it and for me to visualise it's original unbound conformation ( so that i can compare bound and unbound protein). > > In addition, i realised that the PDB file has 20 conformers of the protein-ligand complex. > Therefore I thought that my steps/strategy would be > • split the 20 conformers into submodels > • del ligand and to do a loop on it for the 20 submodels. > • superimpose all 20 conformers (unbound) vs 20 conformers (bound with ligand) > > Please advice if my steps are right or I am missing something. > > PDB file is 2MGY > > Thank you! > > Once again really appreciate all the work and technical advice provided for Chimera > Best > Kei Onn

2 1

Changes in protein stability
by kloe brathon 25 Dec '18

25 Dec '18

Dear Chimera Users, I am studying on aprotein and its interactions with its ligands and I want to explore what wouldbe the effect on protein thermodynamic stability if some parameters were changed such asaddition, removal of hydrogen bonds or other forces. Any idea on how to dothat? I am new on this. Thank you on advance! Kloe

3 4

Topology error
by Gonzalez Fernandez, Cristina 19 Dec '18

19 Dec '18

Dear Chimera users, I want to perform molecular docking by using Swiss Dock. Therefore, I have used Chimera to remove the molecules that I don't want from the PDB file, add hydrogens and save as mol2. However, when I tried to upload the mol2 file in SwissDock I get this error: "Ligand setup failed. Please check that your structure file has a correct topology. No extra info available". Does anyone know what I am doing wrong? Thank you in advance, C.

2 3

Script to minimise the binding site
by Miro Moman 18 Dec '18

18 Dec '18

Hello, I would like to minimise the binding site including ligands, cofactors and water molecules. I have the following script: ___ runCommand("open " + pdbpath + pdbid + "_chimera.pdb") runCommand("findclash 'ligand | solvent' test '~ligand | ~solvent' overlapCutoff -1.0 hbondAllowance 0.0 intraMol false selectClashes true") runCommand("sel up") runCommand("namesel tomin") runCommand("minimize spec tomin fragment true cache true prep true freeze :@ca cgsteps 0") runCommand("write format pdb #0 " + pdbpath + pdbid + "_min.pdb") runCommand("write format mol2 #0 " + pdbpath + pdbid + "_min.mol2") ___ I am facing two issues: 1) Water molecules are deleted by prep. Is there as way of preventing this. I have tried creating a custom preferences file like: echo "{'AddCharge': {'charge method': 'Gasteiger'}," > ${DIR}/chimera_preferences #echo " 'DockPrep': {'delete solvent': 'false'}," > ${DIR}/chimera_preferences echo " 'DockPrep': {'incomplete side chains': 'rotamers'}}" >> ${DIR}/chimera_preferences However, the second option is not recognised. Does it exist and, if so, what would be the correct syntax? 2) The second problem is that the selection is ignored and every atom except CAs is minimised. Another option I have tried be setting prep to false and running it beforehand: models = chimera.openModels.open(pdbpath + pdbid + "_chimera.pdb") prep(models, delSolvent=False) But, again, if I do this, the selection is also ignored. Best, Miro -- Edelmiro Moman, PhD South Ural State University - SUSU Южно-Уральский государственный университет - ЮУрГУ Phone: +7 902 614 73 77 E-mail: miromoman(a)gmail.com https://www.linkedin.com/in/edelmiro-moman-3a9979a/

3 5

Measuring the distance between an atom and the protein surface
by Sergio Garay 18 Dec '18

18 Dec '18

Dear Chimera Users I want to measure the distance between an atom (or group of atoms) and the protein surface. I need a sort of residue depth, so the shortest distance between an atom and the molecular surface would be fine for me. I found that command "measure distance" could help, but it does not appear to be working, because every atom that I choose give aproximately the same value. For example (I have only one molecule loaded in Chimera) :. measure distance #0:1@ca #0 log info: minimum distance from #0:1.B@CA to 1752 atoms, 1 surfaces = 1.4814 measure distance #0:58@ca #0 minimum distance from #0:58.B@CA to 1752 atoms, 1 surfaces = 1.4484 The second selected atom is clearly deeper inside the protein Thank you in advance Sergio -- *Sergio GarayDr. en Ciencias BiológicasFacultad de Bioquimica y Cs. BiológicasUniversidad Nacional del LitoralSanta Fe - ArgentinaC.C. 242 - Ciudad Universitaria - C.P. S3000ZAAArgentinaPh. +54 (342) 4575-213Fax. +54 (342) 4575-221 *

2 2

Re: [Chimera-users] Chimera
by Elaine Meng 16 Dec '18

16 Dec '18

> On Dec 16, 2018, at 6:05 AM, Xhoela Bame <xhoelabame(a)yahoo.com> wrote: > > Hello, > > I hope this message finds you well. > > I had posed a question in chimera website but maybe it did not come to you. > > I am studying ligand interaction with a protein and there are pi pi interaction. I am not sure on what is the principle I have to use to show that there is this type of interaction and illustrate that with chimera. > > Also, when showing H bonds, I want to show residue side chain as well in the picture as open structures. Any suggestion on that? > > I am quite new in using chimera and I would be extremely helpful if you would help me on these questions. > > Best, > Ann Hello, In the future, please send questions to chimera-users(a)cgl.ucsf.edu rather than to me directly, and put something useful about the topic in the Subject line like “showing side chains” or “pi-pi interactions.” I did reply to you already about the pi-pi question but perhaps you did not see the answer. I changed the subject line because “Chimera Usage” was not descriptive. Here is that previous answer: <http://plato.cgl.ucsf.edu/pipermail/chimera-users/2018-December/015270.html> To show the side chains, turn on this option of FindHBond before running the H-bond calculation: "If endpoint atom hidden, show endpoint residue” <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/findhbond/findhbo…> If you click Help on the FindHBond dialog it would show you that page. Or if you are using the commands, command “help hbonds” would show you the “hbond” command help and its “reveal” option to do the same thing. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/hbonds.html> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco

1 0

Question about Gaussion filtering
by CAO, Sheng 13 Dec '18

13 Dec '18

Dear Sir/Madam, I am a Ph.D student from The Chinese University of Hong Kong that have just begun to learn structural biology. I found that the Gaussion filtering in Chimera has a much better result than other programs. And I an quite interested in it. Could you please share the principle of the Gaussion filtering algorithm used in Chimera? Thank you. Best Regards, Cao Sheng Postgraduate of The Chinese University of Hong Kong Major: Chemistry E-mail: 904323223(a)qq.com<mailto:904323223@qq.com> Address: G55, Science Centre South Block, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong P.R.China

2 1

Trajectory superposition question
by Samo Lešnik 13 Dec '18

13 Dec '18

Dear Madam/Sir, I have a long MD trajectory (dcd files), and before performing analysis on it I would like to superimpose every frame to the protein from the first frame or the protein from the average one. I am not sure how can this easily be performed. Thank you for your answer, Samo Lešnik

2 2

An oddity in ribbon.
by Yehuda Halfon 13 Dec '18

13 Dec '18

Hi, I have an oddity when showing ribbon. When I show the loop (see figs) in ribbon I get the small thing in the middle and when I show it in atom the loop is longer. In coot the loop looks fine. Is it in the PDB? is in a chimera error? It only happens in this loop in this PDB. The same loop in other PDBs is fine. Thanks, Yehuda Halfon

2 2

Color subunits for map density
by BuddySphinx 12 Dec '18

12 Dec '18

Dear Chimera developers, I have a quick question about coloring. I have a filament map with multiple monomers, how can I color each monomer density with different color? I have a built model, should I do it based on the atom number or should I segment the filament? Best, Yangqi Sent from Mail for Windows 10

3 6

Chimera Usage
by Xhoela Bame 12 Dec '18

12 Dec '18

Hello, I am new in using chimeraand new in this group. I was wondering if I can ask questions related to thetechniques here. I want to study the pi-pi interactions between a protein andits ligand. Any suggestions on how to do that using chimera? Thanks! Ann

2 1

Programmatic selection and minimisation
by Miro Moman 10 Dec '18

10 Dec '18

Hello, I am trying to use Chimera programmatically in order to automatise a number of tasks. I have tree questions: 1) When I select a zone around the ligand (for instance "runCommand(select #0:501.A zr<5)" the selection level is either atoms or, in this case, residues. Is there a way to select molecules? Because the problem I am finding is that if I run "runCommand(select up)", depending on the PDB file, sometimes I need to do it twice and sometimes three times in order to select the entire molecules (be them proteins or not). I would like to have more control over this function. The purpose being deleting molecules that are far away from the ligand. 2) Right now I am running "DockPrep" followed by "minimize" (without further "prep"). The reason is that "DockPrep" enables me to set options, whereas for "minimize" with "prep" this possibility, if it exists, does not seem to be documented. Is that the case? 3) Finally, in "DockPrep", is there a way to select the charge model explicitly? For instance, to choose Gasteiger charges in order to save time. Kind regards, Miro -- Edelmiro Moman, PhD South Ural State University - SUSU Южно-Уральский государственный университет - ЮУрГУ Phone: +7 902 614 73 77 E-mail: miromoman(a)gmail.com https://www.linkedin.com/in/edelmiro-moman-3a9979a/ <https://www.linkedin.com/in/edelmiro-moman-3a9979a/> <edelmiromoman(a)rcsi.ie>

3 2

Questions about the electric fieldline
by xmgign＠126.com 07 Dec '18

07 Dec '18

Hi I want to make the electric fieldline but there are always some problems. I did this as follows, 1. run add charge to the system 2. run APBS, the I get the electrostatic surface and a file named 1.dx 3. open 1.dx 4.measure fieldLines #0 lines 500 startAbove 10 color pink linewidth 2 then I get the problem : no volume specified I have check the userguide of measure fieldlines, but there is nothing about the volume. measure fieldLines map-model(s) [ lines N ] [ startAbove cutoff ] [ step s ] [ modelId model-number ] [ color line-color ] [ lineWidth width ] [ tubeRadius radius ] [ circleSubdivisions M ] [ markers true|false ] what should I do next? Thanks. Qiao Xue xmgign(a)126.com

2 3

changing atomic radii in Chimera
by Elaine Meng 07 Dec '18

07 Dec '18

Hi Yu Guo, (including chimera-users in the message since it is a general question that other people might be interested in) You can change atomic radii as shown in sphere style with command “vdwdefine,” for example <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/vdwdefine.html> vdwdef -0.2 Ca (subtract from current size) vdwdef 1.0 Ca (set size to specific value) <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/vdwdefine.html> Maybe the single O atoms (those without bonds) are in stick style, however, so you would also need to change them to sphere style to see a difference. Since the molecule also has O you wouldn’t want to use “O” in the commands or you would change them all. Instead you could select them (Ctrl-click on atom) and then use “sel” in the command, e.g. repr sphere sel vdwdef 0.8 sel Actually, if you select the atom(s) another way is to use Selection Inspector (open by clicking green magnifying glass icon near the bottom right of the Chimera window) to change their display style and radius. <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/inspection.html> I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco > On Dec 7, 2018, at 11:05 AM, Yu Guo <yg2(a)kth.se> wrote: > > The movie is fine now! I am now wondering how can I change the atomic radii in Chimera? I find Ca is much too big, and O is too small. See the attached movie.

1 0

mmcif, auth_xx information versus label_xx information
by moocow＠mindless.com 07 Dec '18

07 Dec '18

2 3

Re: [Chimera-users] Breaking down symmetry in Chimera
by Elaine Meng 06 Dec '18

06 Dec '18

Hi Anne, It is recommended to send Chimera questions to chimera-users(a)cgl.ucsf.edu (CC’d here) since others may be able to provide better answers or benefit from the exchange. My guess is that you might instead want to use symmetrical fitting, in which multiple copies of the atomic structure automatically maintain the specified symmetry. Symmetrical fitting is available in the “fitmap” command (not the GUI). See documentation <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/fitmap.html> <http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/midas/fitmap.html#symmetric> and video tutorial <http://www.cgl.ucsf.edu/chimera/videodoc/SymFitDNAb/> The video is >6 minutes but worth watching, because like in that video you may need to first just fit one copy (not using symmetry), then use command “measure symmetry” to annotate the map with its symmetry, and then use command “sym” with “update true” to generate the symmetry copies of the atomic model. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco > On Dec 6, 2018, at 10:32 AM, Jecrois, Anne <Anne.Jecrois(a)umassmed.edu> wrote: > > Dear Dr Meng, > I have a 5A cryoEM map with D3 symmetry, howeve I am having some problem with rigid body fitting since I don't know where one assymmetric unit starts or ends . I was wondering if there is way to break down the symmetry in chimera and extract 1/6 of the map and use that for fitting? > Thanks, > Anne Jecrois > PhD Candidate > UMass Medical School > Schiffer Lab/Royer Lab > 364 Plantation St, LRB 970L > Worcester MA 01605

3 3

Saving mrc EM-map
by Ibrahim M. Moustafa 06 Dec '18

06 Dec '18

Hi All, I'm trying to do the fitting of a model into EM (mrc map) for real-space-refine in phenix.First I read the map and clicked "center" in the Volume viewer. Then I saved the centered map, assuming that the header info will be updated in the saved map.I did the fitting and saved the model relative to the map. Reading the saved map and fitted model back looks OK. However, when I do the real-space-refine in Phenix, the CC-value during the run is really low (0.01) suggesting something is not properly done. I checked the header (using mrcfile) of the saved "centered" map and compared it to the original map and it is the same "0,0,0". Which means chimera did not update the header after centering. I'm not if there is a more proper way to do this! Any advice? Thank you for your help. Ibrahim Ibrahim M.Moustafa, Ph.D. Pennsylvania State University Biochemistry & Molecular Biology Dept. Millennium Science Complex University Park, PA16802 Tel (814)863 5940 Fax (814)865 7927

2 2

join models
by Stewart Morley 05 Dec '18

05 Dec '18

I cannot for the life of me get join models to work. 1. I have two structures. 2. The structures overlap. 3. I align them using matchmaker. 4. I delete the overlapped residue from one chain. 5. I select the appropriate C and N terminal residues 6. I try to use join models under Build structure 7. The apply box remains gray, no matter what residue or atom I select. What are common problems that cause join models to not work? Stewart Morley Brigham Young University

2 2

needing help for separating structures
by Yu Guo 30 Nov '18

30 Nov '18

Dear Sir/Madam, I am using Chimara to display large proteins. It is very nice. 6DHO(PDB structure, see attachment) is a very recent PSII structure consisting both S2 and S3(richer) states, which are highly overlapped in the raw data. I am urgently wondering how can I separate S3 out from the S2/S3 mixture by Chimera, especially the OEY? cluster and all its ligands? Thank you very much! Best wishes

4 12

UCSF import Error
by Cackett, Gwenny 28 Nov '18

28 Nov '18

Hi so I am running Linux Fedora 29 and since updating from Fedora 28 I have noticed my Chimera installation has stopped working - the icon does not open the program. And when I try to run from the command line I get the code below, which I gather is an issue with python importing a module: Traceback (most recent call last): File "/home/gwenny/.local/UCSF-Chimera64-1.12/share/__main__.py", line 69, in <module> value = chimeraInit.init(sys.argv) File "/home/gwenny/.local/UCSF-Chimera64-1.12/share/chimeraInit.py", line 628, in init import chimera File "/home/gwenny/.local/UCSF-Chimera64-1.12/share/chimera/__init__.py", line 2758, in <module> from SimpleSession import BEGIN_RESTORE_SESSION, END_RESTORE_SESSION File "/home/gwenny/.local/UCSF-Chimera64-1.12/share/SimpleSession/__init__.py", line 14, in <module> from save import saveSession, sessionID, noAutoRestore, autoRestorable, \ File "/home/gwenny/.local/UCSF-Chimera64-1.12/share/SimpleSession/save.py", line 13, in <module> from chimera import replyobj, selection, SessionPDBio, version File "/home/gwenny/.local/UCSF-Chimera64-1.12/share/chimera/replyobj.py", line 24, in <module> import Tkinter File "/home/gwenny/.local/UCSF-Chimera64-1.12/lib/python2.7/lib-tk/Tkinter.py", line 39, in <module> import _tkinter # If this fails your Python may not be configured for Tk ImportError: /usr/lib64/libfontconfig.so.1: undefined symbol: FT_Done_MM_Var Any help would be appreciated. Thanks and best wishes, Gwenny Cackett PhD Student RNAP Lab Institute of Structural & Molecular Biology University College London Gower Street, London, WC1E 6BT Phone: 020 7679 3899

2 1