Judith Reeks wrote:
>
> Dear All,
>
>
>
> I am currently refining a structure using the latest experimental
> version of Refmac (5.6) and there seems to be a problem with my Fo-Fc
> map. There is a region where I have fitted residues to the electron
> density but after refinement there is still positive electron density
> assigned to the region despite the fact that residues fit the electron
> density (see link below for a screenshot). Multiple rounds of
> refinement have yet to get rid of this problem. I have checked the PDB
> file and there does not appear to be any problems with this region.
> Has anybody seen something like this before?
>
>
>
> http://i1083.photobucket.com/albums/j382/jreeks/Screenshot2011-03-01at1613402.png
>
>
>
> Regards,
>
>
>
> Judith Reeks
>
> [log in to unmask]
>
> School of Chemistry
>
> University of St Andrews
>
Yes, I have encountered such a situation before, where the occupancy was
not set to 1.0. For some reason the occupancy had been set well below
one. This is the first thing I would check. I can't remember right now
why this had happened.
Fred.
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