Since it could be BME (or oxidized BME which is "EMB-BME") with
alternative conformations, it would be good to look to see if there are
high density peaks, or anomalous density, at this site.
Dale Tronrud
On 5/22/2016 10:27 AM, Agnes Thiane Pereira Machado wrote:
> Dear all,
>
> We are refining a structure and came across a density that looks like a
> ligand, we already tested some alternatives, but no one fitted well,
> that density is in the middle of the tetramer that has 222 symmetry. At
> http://www.uepg.br/iulek/Densities1.html
> I left a number of pictures of this density (fourier difference at 3
> sigma) in several orientations.
>
> What we added during all preparation was: i) purification: phosphate,
> NaCl; ii) concentration: tris, NAD+ ; iii) crystallization: acetate,
> beta-mercaptoethanol, PEG 2000 MME, PEG 1000; no need for cryoprotection.
>
> Would you have any suggestion?
> Thanks,
>
> Agnes Machado
> State University of Ponta Grossa
>
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