[ccp4bb]: TLS REFINEMENT & structure deposition (fwd)

["M.D.Winn" <M.D.Winn@dl.ac.uk>]

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> My question has two parts:
> I am refining a structure that has 222 residues. The current R factore is
> 25% and the Rfree is 31%. When I divided my structure into three fragments
> (according to the gaps present) and enabled the TLS refinement the Rfactor
> as well as the Rfree dropped 5%. I did not observe a particular improvement
> of my maps afterwards and the shifts in the coordinates are minor. Is this
> reasonable ?

Yes. If TLS simply models the smearing of your electron density, then
the R factors will improve while the density remains the same. If this
modelling improves the determination of the average coordinates, and thus
corrects model errors, then the maps can improve. Obviously, this is
problem-dependent.

> If this is acceptable, what is the common praxis for including the TLS
> parameters when depositing structures with to the PDB?
> Any advice is appreciated.

The TLS parameters are included in the PDB header and also in the
data harvesting file. The PDB should be able to process either, though
it's probably safest to alert them to the presence of TLS. 

> 
> Florian Schubot
> 

Cheers
Martyn

-- 


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*                                                                        *
*                  Dr. Martyn Winn                                       *
*                                                                        *
*      Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, ENGLAND     *
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