- ChimeraX-users - RBVI Mailing Lists

ChimeraX 1.8 user manual
by NUR SYAMIM SYAHIRAH MAT HUSSIN 04 Sep '25

04 Sep '25

Hi, I am a new user. I am working on aptamer design. The target is animal protein. However, I am not very capable of using ChimeraX to view my aptamer-binding (after finishing docking). Can I get any tips, manuals, or video demonstrations that relate to the study? Regards PENAFIAN: E-mel ini dan apa-apa fail yang dihantar bersama-samanya ("Mesej") adalah dihasratkan hanya untuk kegunaan penerima yang dinyatakan di atas dan mungkin mengandungi maklumat yang tidak umum, bermilik, istimewa, sulit dan dikecualikan dari penzahiran di bawah undang-undang yang terpakai termasuklah Akta Rahsia Rasmi 1972. BACA SELANJUTNYA... <https://mail.uitm.edu.my/disclaimer> DISCLAIMER : This e-mail and any files transmitted with it ("Message") is intended only for the use of the recipient(s) named above and may contain information that is non-public, proprietary, privileged, confidential and exempt from disclosure under applicable law including the Official Secrets Act 1972. READ MORE... <https://mail.uitm.edu.my/disclaimer>

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Hide missing residues label
by colin＠gauvin.id 04 Sep '25

04 Sep '25

Hello all, If there are a number of missing residues, sometimes there is a label such as "16 residues" at the dashed line where they would be. Is there a way to hide this for figure making? For the life of me, I cannot figure it out. Best, Colin

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residues labels not showing; no error in the log
by Krishnan Raman 04 Sep '25

04 Sep '25

[cid:image001.png@01DC1DA9.88EDB2F0] Residue labels not showing up with no error in the log! I am sure iam missing something. Krishnan Raman Executive Director, Structural Biology BioCryst Pharmaceuticals CONFIDENTIALITY NOTICE This email, including any attachments, may contain confidential or legally privileged information that is intended only for the individual or entity to whom it is addressed. If you are not the intended recipient, please be advised that any dissemination, distribution or copying of this email and any attachment is strictly prohibited. If you have received this email in error, please reply to the sender so that BioCryst Pharmaceuticals, Inc. can take corrective measures and then permanently delete this email and any attachment, including any printed copies. Thank you.

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Cylindrical averaging for radial density profiles
by Dmitry Semchonok 04 Sep '25

04 Sep '25

Dear Colleagues, I need to perform cylindrical averaging of membrane protein density maps (MRC files) to generate radial density profiles for membrane thickness analysis. Does ChimeraX have built-in functionality for this, or are there existing scripts/plugins available? If not, could you provide guidance on the best approach to implement this? Thank you! Kind regards, Dmitry

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How to apply selected graphics JUST to the side chain and not the backbone?
by mfmccl＠berkeley.edu 02 Sep '25

02 Sep '25

Hello all! I can't seem to figure out how to apply selected graphics to give a silhouette on residues of interest without it adding a silhouette to the side chain and the respective backbone cartoon. Is it possible to just select the sidechain atoms only? I've tried my usual tricks but can't seem to get it to work. I've tried "cartoon suppress true" & selecting the individual atoms of the sidechain but it always also selects the cartoon backbone. Thanks! Madi

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Minimize structure capability in chimeraX?
by Kabir Gupta 02 Sep '25

02 Sep '25

Hi all, Does ChimeraX currently have the capability to minimize a structure? The functionality I'm talking about is of the sort available under Tools -> Structure Editing -> Minimize Structure... in the original Chimera. Last I can find is from a mail thread in 2020, at which point this had not yet been implemented in ChimeraX. Is there an acceptable substitute to achieve the same thing now, or do I have to reopen in original Chimera to do minimizations? Thanks very much, Kabir

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An issue with Boltz-2 in ChimeraX daily
by Enrico Martinez 02 Sep '25

02 Sep '25

Dear ChimeraX users! I am testing the Boltz-2 on Mac in the ChimeraX-daily: for one receptor (provided fasta sequence) and 5 ligands (provided smiles strings for each compound). My calculations are running on GPUs and I see the Boltz-2 folder with the results. However, the ChimeraX send the following error message (copied directly from log): Running Boltz prediction of 5 ligands on gpu Using cached multiple sequence alignment Running boltz prediction failed with exit code 1: command: /Users/enrico/boltz22/bin/boltz predict /Users/enrico/Desktop/boltz_2 --accelerator gpu --no_kernels stdout: Boltz version 2.2.0 Checking input data. Processing 5 inputs with 5 threads. Running structure prediction for 5 inputs. Predicting: | | 0/? [00:00<?, ?it/s] Predicting: 0%| | 0/5 [00:00<?, ?it/s] Predicting DataLoader 0: 0%| | 0/5 [00:00<?, ?it/s] Predicting DataLoader 0: 20%|██ | 1/5 [01:55<07:42, 0.01it/s] Predicting DataLoader 0: 40%|████ | 2/5 [03:55<05:53, 0.01it/s] Predicting DataLoader 0: 60%|██████ | 3/5 [05:53<03:55, 0.01it/s] Predicting DataLoader 0: 80%|████████ | 4/5 [07:56<01:59, 0.01it/s] Predicting DataLoader 0: 100%|██████████| 5/5 [09:59<00:00, 0.01it/s]Number of failed examples: 0 Predicting DataLoader 0: 100%|██████████| 5/5 [09:59<00:00, 0.01it/s] Predicting property: affinity Checking input data for affinity. Running affinity prediction for 5 inputs. stderr: 0%| | 0/5 [00:00<?, ?it/s] 20%|██ | 1/5 [00:05<00:23, 5.78s/it] 100%|██████████| 5/5 [00:05<00:00, 1.17s/it] GPU available: True (mps), used: True TPU available: False, using: 0 TPU cores HPU available: False, using: 0 HPUs /Users/enrico/boltz22/lib/python3.11/site-packages/pytorch_lightning/trainer/connectors/logger_connector/logger_connector.py:76: Starting from v1.9.0, `tensorboardX` has been removed as a dependency of the `pytorch_lightning` package, due to potential conflicts with other packages in the ML ecosystem. For this reason, `logger=True` will use `CSVLogger` as the default logger, unless the `tensorboard` or `tensorboardX` packages are found. Please `pip install lightning[extra]` or one of them to enable TensorBoard support by default Mon Sep 1 14:38:24 2025: Loading Boltz structure prediction weights /Users/enrico/boltz22/lib/python3.11/site-packages/pytorch_lightning/utilities/migration/utils.py:56: The loaded checkpoint was produced with Lightning v2.5.0.post0, which is newer than your current Lightning version: v2.5.0 Mon Sep 1 14:38:35 2025: Finished loading Boltz structure prediction weights Mon Sep 1 14:38:35 2025: Starting structure inference /Users/enrico/boltz22/lib/python3.11/site-packages/pytorch_lightning/trainer/connectors/data_connector.py:420: Consider setting `persistent_workers=True` in 'predict_dataloader' to speed up the dataloader worker initialization. /Users/enrico/boltz22/lib/python3.11/site-packages/torch/utils/data/dataloader.py:684: UserWarning: 'pin_memory' argument is set as true but not supported on MPS now, then device pinned memory won't be used. warnings.warn(warn_msg) Mon Sep 1 14:38:44 2025: Begin structure inference ligand4 (1 of 5) /Users/enrico/boltz22/lib/python3.11/site-packages/boltz/model/loss/diffusionv2.py:51: UserWarning: The operator 'aten::linalg_svd' is not currently supported on the MPS backend and will fall back to run on the CPU. This may have performance implications. (Triggered internally at /Users/runner/work/pytorch/pytorch/pytorch/aten/src/ATen/mps/MPSFallback.mm:15.) U, S, V = torch.linalg.svd( Mon Sep 1 14:40:40 2025: End structure inference ligand4 (1 of 5) Mon Sep 1 14:40:40 2025: Begin structure inference ligand5 (2 of 5) Mon Sep 1 14:42:40 2025: End structure inference ligand5 (2 of 5) Mon Sep 1 14:42:40 2025: Begin structure inference ligand2 (3 of 5) Mon Sep 1 14:44:38 2025: End structure inference ligand2 (3 of 5) Mon Sep 1 14:44:38 2025: Begin structure inference ligand3 (4 of 5) Mon Sep 1 14:46:41 2025: End structure inference ligand3 (4 of 5) Mon Sep 1 14:46:41 2025: Begin structure inference ligand1 (5 of 5) Mon Sep 1 14:48:44 2025: End structure inference ligand1 (5 of 5) Mon Sep 1 14:48:57 2025: Finished structure inference Mon Sep 1 14:48:57 2025: Loading affinity prediction weights Traceback (most recent call last): File "/Users/enrico/boltz22/bin/boltz", line 8, in <module> sys.exit(cli()) ^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/click/core.py", line 1157, in __call__ return self.main(*args, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/click/core.py", line 1078, in main rv = self.invoke(ctx) ^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/click/core.py", line 1688, in invoke return _process_result(sub_ctx.command.invoke(sub_ctx)) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/click/core.py", line 1434, in invoke return ctx.invoke(self.callback, **ctx.params) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/click/core.py", line 783, in invoke return __callback(*args, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/boltz/main.py", line 1419, in predict model_module = Boltz2.load_from_checkpoint( ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/pytorch_lightning/utilities/model_helpers.py", line 125, in wrapper return self.method(cls, *args, **kwargs) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/pytorch_lightning/core/module.py", line 1581, in load_from_checkpoint loaded = _load_from_checkpoint( ^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/pytorch_lightning/core/saving.py", line 63, in _load_from_checkpoint checkpoint = pl_load(checkpoint_path, map_location=map_location) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/lightning_fabric/utilities/cloud_io.py", line 60, in _load return torch.load( ^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/torch/serialization.py", line 1491, in load with _open_zipfile_reader(opened_file) as opened_zipfile: ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/enrico/boltz22/lib/python3.11/site-packages/torch/serialization.py", line 771, in __init__ super().__init__(torch._C.PyTorchFileReader(name_or_buffer)) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ RuntimeError: PytorchStreamReader failed reading zip archive: failed finding central directory Could you precise which package causes this issue and how would the problem be solved in the ChimeraX update? Many thanks for help!! Enrico

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Boltz-2 in ChimeraX daily
by Enrico Martinez 02 Sep '25

02 Sep '25

Dear ChimeraX users! I am testing the Boltz-2 on Mac in the ChimeraX-daily: for one receptor (provided fasta sequence) and 5 ligands (provided smiles strings for each compound). My calculations are running on GPUs and I see the Boltz-2 folder with the results. However, the ChimeraX send the following error message (coppied directly from log):

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Publication Request
by Russell Couch 29 Aug '25

29 Aug '25

Hello UCSF! My name is Russell and I am a 17 year old student seeking approval from the developers to use ChimeraX in the publication of educationally-intended (not commercially-intended) content I would like to design using the program and animate separately. I would like to use ChimeraX to, for example, compile individual proteins into a complete infectious pathogen in order to demonstrate the roles of individual proteins in the process of infection, disease progression, and possible treatment. I want to firmly state that my personal purpose of the publication is educational, though I understand YouTube is inherently a commercial platform. When complete, the videos would be uploaded to a brand new, unmonetized channel dedicated to my educational publications. There would be no other co-collaborators, as in people frequently working with me and using ChimeraX to produce educational content. This is a personal project and I would be the only one using the program to produce my content. If another creator wanted to collaborate with me using their own research and resources (assuming they have all the proper permission like I'm asking for), would that be allowed, assuming the collaboration is occasional and on a per-video basis rather than consistent or unifying, such as two channels deciding to join together? On a bit of a more personal note, I am applying to college soon and am very interested in a couple of colleges in California. I am very passionate about engineering, particularly chemical engineering, and I believe the cures of tomorrow are waiting to be discovered. I am on a mission to discover them and make them available to all. While I am determined to be the change I want to be no matter where I go, I would like to attend a good engineering school if possible, and am personally very attracted to the idea of going to college in California. Some of the very best engineering schools in the country are in California, and getting into them would be a dream come true, though I am realistic and prepared to achieve my goals without any of their external resources. These resources, while valuable, mean nothing without the internal drive to strive. Regardless of acceptance, the colleges in California most intriguing to me are UCB, Caltech, and Stanford, though UCSD, Irvine, Davis, and many other schools there all have fantastic engineering programs, and are more statistically favorable in terms of acceptance, though still quite selective. I know UCSF is a medical school, but it shares with these colleges very high selectivity, and I would love to gather any potential advice, especially coming directly from another top college. I greatly appreciate you taking the time to read my request and am very excited to use ChimeraX, whether for personal or educational use. Sincerely, Russell Couch

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Coloring different regions
by Vojo P Deretic 29 Aug '25

29 Aug '25

Hi How to color different domains in a structure in ChineraX. I tried selecting residues on the sequence and can get an outline over the selection but how do I color different regions and keep all of them differently colored plus save the work? Thanks Sent from my iPhone with lots of typos and autocorrect nonsense - my apologies...

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ISOLDE installation error
by Zhou, Tongqing (NIH/VRC) [E] 27 Aug '25

27 Aug '25

Dear All, I am having problem install ISOLDE on a new MacBook. My ChimeraX version is 1.10rc202505310246 (2025-05-31). When installing from Toolshed, it says: ERROR: Could not find a version that satisfies the requirement ChimeraX-Core~=1.10.0 (from chimerax-isolde) (from versions: none) ERROR: No matching distribution found for ChimeraX-Core~=1.10.0 Best regards, Tongqing Tongqing Zhou, Ph.D. Principal Investigator and Chief Structural Virology and Vaccinology Section Structural Biology and Structural Bioinformatics Cores Vaccine Research Center (VRC), NIAID National Institutes of Health Building T40, Room 117 (Office) Building 40, Room 4609B (Lab, shipping) 40 Convent Drive, Bethesda, MD 20892 Office: (301) 761-7068 Cell: (240) 695-0536 https://www.niaid.nih.gov/research/tongqing-zhou-phd tzhou(a)nih.gov<mailto:tzhou@nih.gov>

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Displaying maps with threshold defined by mapstats
by Grundmann,Lorenz Emanuel 27 Aug '25

27 Aug '25

Dear ChimeraX-Team and all, I want to visualize multiple cryoEM maps in a comparative manner. Therefore, I would like to display them with a threshold level of e.g. 90% their maximum voxel value. Is this possible in chimerax? Any help would be greatly appreciated. Thank you. Best, Lorenz

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aborting slow hbonds command
by Daniel Larsson 25 Aug '25

25 Aug '25

Is it possible to prematurely stop a command issued on the command line that takes too long time? I often have sessions with many (more than 20) large ribosome structures open at the same time. I sometimes mistype the restrict atom-spec2 argument for the hbonds command and ChimeraX goes through each of the structures one by one twice, which can take very long time. I wish there were a flag to the hbonds command to only consider the models in atom-spec1, so that those typos does not spawn a search across all models. In addition, it would be great if the code for the hbonds command could be optimized. Why iterate over all models if only atoms in one model are in atom-spec1? Regards, Daniel När du har kontakt med oss på Uppsala universitet med e-post så innebär det att vi behandlar dina personuppgifter. För att läsa mer om hur vi gör det kan du läsa här: http://www.uu.se/om-uu/dataskydd-personuppgifter/ E-mailing Uppsala University means that we will process your personal data. For more information on how this is performed, please read here: http://www.uu.se/en/about-uu/data-protection-policy

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ISOLDE released for ChimeraX 1.10
by Tristan Croll 22 Aug '25

22 Aug '25

Hi all, Just a note for ISOLDE users: ISOLDE 1.10 is now out on the TooShed, ready for use with ChimeraX 1.10.x. Please enjoy! Best, Tristan -- Altos Labs UK Limited | England | Company reg 13484917 Registered address: 3rd Floor 1 Ashley Road, Altrincham, Cheshire, United Kingdom, WA14 2DT

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Model-Map coloring using the ChimeraX
by Andrew Mugo 21 Aug '25

21 Aug '25

Dear ChimeraX user support team, I am having a problem of coloring map based on the model color. I uninstalled and re-installed ChimeraX 1.9/1.10 but when I try to color the map, the software gives electrostatic color like. Please let me know how I can solve this problem. Best regards, Andrew

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Residue Interaction Network visualisation using chimerax
by Gagandeep Singh 20 Aug '25

20 Aug '25

Dear team , I have generated residue interaction network (RIN) data using RING 4.0 and would like to visualize this . I am familiar with UCSF Chimera, which supports visualization of RIN data, and I was wondering if ChimeraX also offers similar functionality. Kind regards -- *गगनदीप सिंह **/ Gagandeep Singh* *डॉक्टरेट का विद्यार्थी **/ Doctoral student* *ब्रिक - ट्रासलेशनल स्वास्थ्य विज्ञान और प्रौद्योगिकी संस्थान* *BRIC- Translational Health Science and Technology Institute* *(भारत सरकार के जैव-प्रौद्योगिकी विभाग का एक स्वायत्त संस्थान)* *(An autonomous institute of the Dept of Biotechnology, Govt Of India)* *NCR Biotech Science Cluster,* *3rd Milestone, Faridabad–Gurugram Expressway,* *PO box #04, Faridabad- 121001 (Haryana)*

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Question about the software features
by Mazrouee, Sepideh (NIH/OD) [E] 19 Aug '25

19 Aug '25

Hi, I had the chance to use ChimeraX recently for aligning some predicted protein 3D structures and it looks wonderful. However, I need to do some labeling of the visualization (including labeling of specific protein domains) and I wasn't sure if such feature exists in the software or there might be a way to make it happen. I would highly appreciate your help if you could provide me with some online resources to educate myself or join a call with some team members to help us out. Best regards, Sepid Sepideh Mazrouee, PhD Researcher, Office of Data Science Strategy (ODSS) Office of Director, National Institute of Health (NIH<https://www.nih.gov/>)

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Select atoms/chains by _atom_site.label_asym_id instead of _atom_site.auth_asym_id?
by Ute Roehrig 19 Aug '25

19 Aug '25

Hello, Is there a way to select atoms/chains from a mmcif file by their _atom_site.label_asym_id value instead of the _atom_site.auth_asym_id value? Thank you for your help, Ute

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Question Regarding Contacts Command in ChimeraX
by Andrew Guo 19 Aug '25

19 Aug '25

Hello, My name is Andrew Guo, an undergraduate at the University of Maryland College Park, doing research under Dr. John Orban with help from Dr. Andy LiWang from the University of California Merced, in the field of protein fold switching. Dr. LiWang recently used ChimeraX to calculate vdW contacts closer than 3.8 A between carbons in the context of a fold switching region in a small list of 26 "metamorphic" proteins (see here <https://doi.org/10.1073/pnas.2422725122>). I am now working on automating the whole process of calculating these contacts. In doing so, I have encountered a strange inconsistency that I do not know how to fix, and was hoping to gain some insight from the people who have developed ChimeraX. Previously, the overall contacts count was calculated by first calculating interdomain contacts then intradomain contacts and summing the two. It would be much simpler to calculate the contacts in one "whole" command instead of restricting the command to just interdomain or intradomain contacts. However, I have found that this "whole" command sometimes includes ligand contacts. For instance, for the pdb code 4O01A and region of interest residues 446-478, I have the following set of commands: interdomain: contacts /A:446-478@C* restrict /A:1-445,479-506@C* distance 3.8 reveal true name vdW output 13 intradomain: contacts /A:446-478@C* restrict /A:446-478@C* distance 3.8 reveal true name vdW output 8 "whole": contacts /A:446-478@C* restrict /A@C* distance 3.8 reveal true name vdW output 22 Obviously, 13 and 8 do not sum to 22. Ligand command: contacts /A:446-478@C* restrict ligand distance 3.8 reveal true name vdW This ligand command had an output of 1 and was the following: /A LEU 463 CD1 /A LBV 600 CMA (alt loc A) This contact was also the extra contact found in my "whole" command output, so I could just run the two commands (whole and ligand) and subtract the output of the ligand command from the output of the whole command. However, for the pdb code 3KMZA and region of interest residues 393-421, I have the following: interdomain: contacts /A:393-421@C* restrict /A:1-392@C* distance 3.8 reveal true name vdW output 0 intradomain: contacts /A:393-421@C* restrict /A:393-421@C* distance 3.8 reveal true name vdW output: 1 distances atom1 atom2 distance /A MET 400 CG /A GLU 401 C 3.788 "whole": contacts /A:393-421@C* restrict /A@C* distance 3.8 reveal true name vdW output: 1 distances atom1 atom2 distance /A MET 400 CG /A GLU 401 C 3.788 ligand: contacts /A:393-421@C* restrict ligand distance 3.8 reveal true name vdW output 6 1-6 = -5 contacts Using my method, I get -5. Clearly, this is bad. The ligand command gave these 6 contacts: 6 distances atom1 atom2 distance /A THR 397 CG2 /A GOL 3 O3 3.321 /A ARG 394 CD /A GOL 3 O2 3.411 /A ILE 396 CA /A GOL 3 O3 3.436 /A ILE 396 CG2 /A GOL 3 O2 3.667 /A ILE 396 C /A GOL 3 O3 3.703 /A ILE 396 CB /A GOL 3 O3 3.721 However, these contacts were not part of the output of the whole command, unlike in the case of 4O01A. Is there something I am doing wrong with how I am setting up my commands? Please let me know if further information is needed! Thank you, Andrew

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Log Setting
by NUR AIDA SAKINAH 18 Aug '25

18 Aug '25

Hi ChimeraX teams, I am using ChimeraX version 1.9 in dark theme, when open the saved session, the log shown in highlighted grey colour if i’m not mistaken. So, is there a setting to make it easier to view the log for the saved session? Thank you. Regards, Aida

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B-factor and error in distance measurements
by Charles Midgett 18 Aug '25

18 Aug '25

I have two structures of a protein solved to different resolutions, one pretty good and the second not so good, and I want to compare distances between congruent atoms in the structures. It occurred to me that I have no idea if the differences in the distances are within the positional error of the atoms or not. Therefore, is there a way to propagate the positional uncertainty in the B-factors into a linear distance uncertainty? Sincerely, Charles

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Multiple sequence alignment display
by Betancurt, Leonardo 18 Aug '25

18 Aug '25

Hello, I would like to display a multiple sequence alignment based on structure after match maker. I use the command ”mm #!1-4 to #5 showAlignment true” but ChimeraX shows multiple pairwise alignments, is there a way to create a multiple sequence alignment? Thank you, Leo Betancurt, Ph.D. Post Doctoral Researcher | Zatopek Lab<https://www.neb.com/en-us/research-labs/zatopek-lab?srsltid=AfmBOoqPDIvrCfa…> New England Biolabs Inc. 📞 (978) 380-7290 📱 (351) 350-4075 [signature_474729057]<http://www.neb.com/>

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Re: ChimeraX support: Alphafold contacts
by Elaine Meng 14 Aug '25

14 Aug '25

Hi Tony! There are lots of options in menu: Select... Contacts, so it rather depends on all of the specific settings that you chose. Here is the help for that GUI: <https://rbvi.ucsf.edu/chimerax/docs/user/selectcontacts.html> To summarize in regard to your questions... If you are in the Chains tab, you have a choice to use atomic distance or buried surface area. If you chose atomic distance it is using all the atoms and doesn't care what is backbone or sidechain. It would be the minimum distance (closest pair). At any point you can just simply list the residues in the current selection, e.g. command info residues sel ... which will go to the Log but you could alternatively save to file, e.g. info residue sel saveFile ~/Desktop/contacts.txt If you are in the Atomic tab, then you have the choice to use VDW overlap (negative distance between VDW surfaces) or center-center distance as the main criterion. If using that tab, presumably you would have already selected one of the chains and then designate to limit the results to atom pairs where one of the atoms is selected. You don't have to go through GUIs. If you just want to list residues in one chain with any atom within some distance of any atom in another chain, you could use commands like the following to select protein residues in chain A within 5.0 Angstroms of protein residues in chain C. The "protein" intersections are because some structures have water, ligand, ions with the same chain IDs as the protein chains, but I wanted to only consider the protein. select (/A & protein) & (/C & protein) :<5.0 info residues sel If the chains were only protein anyway, or you wanted to include any nonprotein residues, could be simpler select /A & /C :<5.0 See command-line zone specification and combinations such as intersection (&): <https://rbvi.ucsf.edu/chimerax/docs/user/commands/atomspec.html#zones> Again it is all atoms and the closest pair. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Resource for Biocomputing, Visualization, and Informatics Department of Pharmaceutical Chemistry University of California, San Francisco > On Aug 10, 2025, at 5:39 PM, Anthony Newcombe <anthony.newcombe(a)appliedbiopharm.com> wrote: > > Hello Elaine > > I have a commercial license of ChimeraX. Further to the email below, I have been using the menu and GUIs to select > contacts as described in your online message below > > https://mail.cgl.ucsf.edu/mailman/archives/list/chimerax-users@cgl.ucsf.edu… > > This highlights the residues, and returns ' 267 atoms, 264 bonds, 32 residues, 1 model selected' between chains A and C > > But is there a simple command to list the identified residues as an output that are within less than 5 Angstroms and may interact for chain A or chain C, ie > > LEU264 > SER265 > ALA266 > > Also one question regarding the atomic distance used, is this a max distance between side chains, or the distance between the peptide backbones? > > Thanks for the help and apologies if these are simple questions > > Many thanks > > Tony

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Assistance: ChimeraX morph
by Priyanka Abeyrathne 12 Aug '25

12 Aug '25

Hi, I have two cryo-EM models (PDBs) at neutral and acidic pH conditions, both containing 486 amino acids. I would like to compare them by calculating the RMSD per residue, and then generate a morphing animation between the two structures. I used the following commands in ChimeraX: 1. I aligned the two structures using MatchMaker: mm #1 to #2 showAlignment true 2. I clicked on one amino acid in the MatchMaker alignment results to highlight the aligned residues. 3. Then I used the command: select ~sel to select residues with an RMSD greater than 1 Å. 4. To visualize the atoms of the selected residues with high RMSD, I ran: display sel & protein 5. I then cleared the selection using: select clear 6. Finally, I attempted to generate a morphing animation using: morph #1,2 wrap true frames 60 However, this command did not work. Could you please help me troubleshoot this? Thank you. Kind regards, Priyanka

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Creating an AtomicStructure object (along with other atomic objects) from scratch using Python API
by nrajan53045＠utexas.edu 11 Aug '25

11 Aug '25

Hi there, I am new to ChimeraX and its python API. As I was looking through the documentation, I noticed there were some atomic data classes (AtomicStructure, Atom, Atoms, Residue). Say I have a PDB file with information about all the atoms in the model, am I able to simply create Atom objects from reading the PDB file and, consequently, add these Atom objects to an AtomicStructure object? The reason I want to do this is because I want to use the fitmap function while limiting any disk IO. So, opening the file in ChimeraX (even if using the no gui offscreen functionality) would not work. I thought of simply creating objects from scratch, but I am running into errors when instantiating them. Sorry if this is an obscure problem or if I was unclear. Thanks for your help! Best, Nikhil

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