[chimerax-users] Can ChimeraX morph between two surfaces?

[Elaine Meng]

Hi Steve,
Actually I’m surprised the Mg and water were included (even if present at both ends) because I thought they had to be tethered by a bond or pseudobond (like a distance measurement) to the biopolymer chain, as described here under “Atoms in Common”:

<http://rbvi.ucsf.edu/chimerax/docs/user/commands/morph.html#pairing>

For the case where composition changes, you could add in a fake Mg ion and water to the structure that’s missing them, but you’d have to decide where to put them.  Also it was my understanding that they had to be tethered to the biopolymer chain (e.g. add distance measurement, which can then be hidden), but maybe that requirement has changed, or the Mg does already have a metal-coordination pseudobond to the biopolymer.

Or if you don’t care if the Mg or water move during the morph, you could just display those atoms from the original model (that was input to morphing) even though they are not present in the trajectory.
Elaine
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Elaine C. Meng, Ph.D.
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

> On Feb 14, 2019, at 12:51 PM, Steve Chou <stevezchou at gmail.com> wrote:
> 
> Thanks, Elaine! 
> You command "rainbow structures" works beautifully. 
> There is "a Mg ion" and "a water molecule" in the two conformations.
> (1) If the two conformations have exactly the same compositions (by shifting the structure), the  "Mg ion" and the "water molecule" do not follow the same path as the protein.  They move but separate from the protein.
> (2) If the two conformations have slightly different compositions, the "Mg ion" and the "water molecule" do not show up in the morphed pdb ensemble.
> Is there a way to morph the specific components properly?
> Steve
>