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On Tue, 22 Aug 2006, Mario Sanches wrote:

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> Dear All,
> 
> I am on the final stage of refinement and  I am making sure, on coot, 
> that the residues are in the allowed regions of the Ramachandran Plot. 
> The problem is that, after Refmac, those residues are thrown back on the 
> disallowed regions.
> 
> This a low resolution structure (3.35A). I am using a matrix weight 
> which renders a RMSD bond of 0.02A. Since it is very low resolution, I 
> thought it would be a good idea to keep all residues in the allowed 
> regions. Is there any way to tell Refmac to keep it there?
> 
> Thank you in advance,
> 
> Mario Sanches

Hi,

I know that I'm not answering your question, however I noticed something
weird about the use of Refmac you mention:

at the resolution you're working at (I suppose given by your crystals, not
by choice I assume) the RMSD on bond lengths should be ca. 0.012, not 0.02
A.

Thus my guess is that the geometry is poorly restrained, too much weight
given on the X-ray term during refinement.

Perhaps you should adjust the weight so that the geometry is restrained
more tightly and see how it goes.

Fred.

-- 

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