[Chimera-users] Relative exposure of amino acids

[Elaine Meng]

Hi Agne,
If you were using the steps on this page:

<http://www.rbvi.ucsf.edu/chimera/docs/UsersGuide/surfnorm.html>

... then the "relSESA" values are the surface area of the specific residue normalized (divided) by the surface area of that same type of residue in the middle of a Gly-X-Gly tripeptide.  The GXG tripeptide is just meant to represent a fully exposed state of that type of residue.

For example, 1.0 is totally exposed (same as in GXG tripeptide), 0.2 is 20% exposed compared to the GXG tripeptide, 0.0 is fully buried, etc.

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

> On May 16, 2020, at 12:08 AM, <agnek54 at gmail.com> <agnek54 at gmail.com> wrote:
> 
> Hello,
>  
> I would like to consult on relative exposure of amino acids calculations interpretation. I performed the steps for relative amino acid exposure calculation for my structure, however I am a bit lost on how to interpret the results. Since the parameter used for calculation is solvent excluded area, I am a little bit confused about relSESA attribute values meaning: does the highest value for relSESA attribute show that residue is highly exposed, or highly buried in the structure?
>  
> Sincerely,
> Agne