Are you sure of your spacegroup?
eleanor
Check for Se by doing an anomalous difference map using the PHIC FOM
output by refmac.
You will have to CAD together the two files - one with the Dano from the
data processing with the REFMAC output before doing the map.
eleanor
Sampath Natarajan wrote:
> Dear all,
>
>
>
> Now I'm solving a structure with 1.6A resolution. The data seems good with
> R-sym (12.4) and all other parameters. Actually the data was collected with
> SAD phasing. When we checked the data we couldn't find the Se atom in the
> structure. Since the data resolution is good, we tried to do molecular
> replacement using Balbes program. It was selected a model with 25% sequence
> identity and we got the good solution too. I could find all residues in the
> density and also checked the Ramachandran map which shows almost all
> residues are in the allowed region.
>
>
>
> The problem is, I have done refinement many times, the R-factor (45.3) and
> R-free (51.4) is not reducing during the refinement and also figure of merit
> is not increasing. Still it remains what I got during the first refinement.
> The density is also not improving much. Also I could find many cuts in the
> density.
>
>
>
> My question is……..
>
>
>
> 1. Can we use SAD phasing data for MR solution?
>
> 2. Is there any other way to reduce the R/R-free?
>
> 3. Why the figure of merit is not increasing even after modeled the
> residues exactly into the electron density?
>
>
>
> Thanks,
>
>
>
> Regards,
>
>
>
> Sampath
>
>
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