AMBER Archive (2005)

Subject: Re: AMBER: is calculated B-factors always smaller than experimental ones?

From: Carlos Simmerling (carlos_at_ilion.bio.sunysb.edu)
Date: Sun Aug 07 2005 - 10:23:42 CDT


is your simulation at the same temperature as the xray experiment?
only then would you expect thermal fluctuations to have the
same magnitude. also, unless you simulate the crystal you cannot expect
the same fluctuations.

haixiao jin wrote:

>It is said that the crystallographic B-factor measures both the
>thermal fluctuation (including conformational heterogeneity of
>proteins) and global translation and rotation. In our calculation
>B-factors, however, the global translation/rotation has been removed
>by rigid-body alignment. Therefore, one might expect that the
>calculated B-factors should be smaller than the experimental ones.
>But the calculated B-factors I have obtained are larger than the
>experimental ones. Here in my bfactor.in file.
>
>Bfactor.in:
>
>trajin 1npt.mdcrd
>reference min.pdb
>center :1-373 origin mass
>image origin center familiar
>rms reference out protein.out :1-372_at_CA
>rms reference out ligand.out :373
>atomicfluct out bfactor.out @CA byatom bfactor
>
>Is that anything wrong with my bfactor.in? thank you for your suggestion!
>-----------------------------------------------------------------------
>The AMBER Mail Reflector
>To post, send mail to amber_at_scripps.edu
>To unsubscribe, send "unsubscribe amber" to majordomo_at_scripps.edu
>
>

-- 
===================================================================
Carlos L. Simmerling, Ph.D.
Associate Professor           Phone: (631) 632-1336
Center for Structural Biology Fax:   (631) 632-1555
Stony Brook University        Web:   http://comp.chem.sunysb.edu/carlos
Stony Brook, NY 11794-5115    E-mail: carlos.simmerling_at_stonybrook.edu
===================================================================

----------------------------------------------------------------------- The AMBER Mail Reflector To post, send mail to amber_at_scripps.edu To unsubscribe, send "unsubscribe amber" to majordomo_at_scripps.edu