Dear Madhan, I don't understand "not able to lock" in ChimeraX or "not able to move" in Chimera.

In Chimera, you can control whether each model is hand-movable or not by checking/unchecking the "A" (activated) boxes in the Model Panel, as discussed here: http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/mouse.html#activedef

Show the Model Panel from the Chimera Favorites menu.

By hand you can then move the atomic model to roughly the correct place in the map before optimizing the fit with Fit in Map.

The ChimeraX tool Fit in Map is basically the same as the Chimera tool. However, in ChimeraX, the way to move just one model is to select some part of it (Ctrl-click) and then use the mouse mode "move selected models" as discussed in this earlier post: http://www.rbvi.ucsf.edu/pipermail/chimerax-users/2017-November/000157.html

Also if you additionally press Shift, that mode switches between rotate and translate. http://rbvi.ucsf.edu/chimerax/docs/user/tools/mousemodes.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 Mar 12, 2020, at 6:23 PM, Tirumalai, Madhan R mrtirum2@Central.UH.EDU wrote:

Dear Elaine

Thank you - all those tips were useful.

With ChimeraX, am not able to lock the Cryo-EM density map and then use the crystal structure to fit into it.

Whereas Chimera allows me to do so - however am not able to move the crystal structure to superimpose on the CryoEM density to do the 'Fit in Map'

is it something am not doing right? I follow these instructions - https://www.cgl.ucsf.edu/chimera/data/tutorials/volumetour/volumetour.html#f...

From: Elaine Meng meng@cgl.ucsf.edu Sent: Wednesday, March 11, 2020 5:22 PM To: Tirumalai, Madhan R mrtirum2@Central.UH.EDU Cc: ChimeraX Users Help chimerax-users@cgl.ucsf.edu Subject: Re: [chimerax-users] Making movies and fitting structures into cryoEM

Dear Madhan, Although ChimeraX doesn't yet have a movie-making dialog (GUI), you can make movies with ChimeraX command scripts. In a command script (plain text file named ending in .cxc), the "movie" command does recording and creating a movie file, whereas other commands (show/hide, color, turn, 2dlabel, etc.) can be used to control display, motions, and labeling... whatever you want to happen during the movie. Simply opening the .cxc file runs the commands.

You can change volume thresholds with the "volume" command "level" option, for example:

volume #1 level 0.08

http://rbvi.ucsf.edu/chimerax/docs/user/commands/volume.html#general

To gradually change the threshold over multiple display frames, you can combine the "volume" command with the "perframe" command, for example:

perframe "volume #2 level $1" range 0.1,0.3 frames 120; wait 120

(those should be plain text quotation marks, although the e-mail display may change them to fancy quotation marks)

http://rbvi.ucsf.edu/chimerax/docs/user/commands/perframe.html

See ChimeraX "making movies" page and links therein: http://rbvi.ucsf.edu/chimerax/docs/user/movies.html

...including movie-making tutorials: http://www.rbvi.ucsf.edu/chimera/data/sbgrid-apr2017/cryomovie.html http://www.rbvi.ucsf.edu/chimerax/data/movies-may2019/moviemaking.html

See also general information on ChimeraX command files: http://rbvi.ucsf.edu/chimerax/docs/user/commands/usageconventions.html#cxc-files

For your other question, if you are asking how to fit an atomic structure into a map, see the "Fit in Map" tool and/or "fitmap" command: http://rbvi.ucsf.edu/chimerax/docs/user/tools/fitmap.html http://rbvi.ucsf.edu/chimerax/docs/user/commands/fitmap.html

Or to compare one atomic structure to another atomic structure, you can superimpose them with the "matchmaker" command: http://rbvi.ucsf.edu/chimerax/docs/user/commands/matchmaker.html

Chimera has a Matchmaker GUI, but ChimeraX does not have the GUI yet, only the command.

I hope this helps, Elaine

---

Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco

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Begin forwarded message:

From: "Tirumalai, Madhan R" Subject: ChimeraX Date: March 11, 2020 at 1:10:41 PM PDT To: "goddard@cgl.ucsf.edu" goddard@cgl.ucsf.edu

Dear Dr. Goddard

Warm Greetings!

We have been using ChimeraX to look at mrc files.

While I am able to use the "Spin movie" option, am not able to use the make movie option, which I could with the Chimera version.

I would much appreciate if you could kindly let me know how:

I can use the movie making option to make movies using different images with increasing/ decreasing thresholds (Volume Viewer)?

Since am not familiar with docking programs, I would like to know how can one a related crystal structure into a new Cryo-EM structure to show the differences between the crystal structure and the Cryo-Em?

Thanks Madhan