Hi Alexei,
at this resolution you most likely need to refine isotropic group B (one
B per residue or so) or/and do TLS refinement (on top of it).
Cheers,
Pavel.
---
Pavel V. Afonine, Ph.D.
Lawrence Berkeley National Lab, Berkeley CA, USA (http://www.lbl.gov/)
CCI: Computational Crystallography Initiative (http://cci.lbl.gov/)
PHENIX (http://phenix-online.org/)
On 3/26/2008 10:49 AM, Alexei Datsuk wrote:
> Hi,
>
> I have a question with B-factor and TLS refinement. My protein
> diffracts only to modest/low resolutions (3.4 A). I've been refining
> isotropic B-factors for main chain and side chain (not individual
> atoms) because I'm worried at this resolution I don't have enough
> observations to justify individual B-factor refinement.
>
> First question: Is this a good assumption on my part, or should I try
> refining individual B-factors and look at how R/Rfree behaves? I just
> don't want to be over-refining my structure.
>
> Second question: Can I do TLS refinement at low resolution when
> B-factors are only refined for main chain and side chain? I would
> imagine that I need to be refining individual B-factors.
>
> Third question: Is it justified for me to be doing TLS refinement at
> these resolutions?
>
> Thanks
>
> Alexei
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