***  For details on how to be removed from this list visit the  ***
***          CCP4 home page http://www.ccp4.ac.uk         ***




It seems to me that the best solution here would be to model what is
actually going on: disorder.  For the example of a lysine where there is
limited or poor electron density beyond the C-beta, the best
representation of the physical model would be an ensemble of all
possible rotamers of what is physically present in the crystal.  Having
"N" sidechains (alternate conformers) with occupancies of 1/N would be
extremely clear to all users (novice and expert alike) as well as most
if not all software.

-Tom




I am actually of the same opinion...I think that a representation like
this is supported fairly well by theory.

But the idea of modeling more when you observe less is scary to me.

What does this mean in the limit....

Should we use a kinematics approach to build all possible
conformations for a disordered loop and assign occupancies by the
density of the Ramachandran plot?

or

Should a 3.5 Angstrom structure with little sidechain density really
have several alternate conformations?

-bob

Reply via email to