Hi,

I don't think you would get such low R-factors so readily if you were missing half the structure. 73% solvent is unlikely but not impossible. If you look at the packing, is there a connected lattice that could form a plausible crystal?  If your protein is a dimer, is there an appropriate dimer generates by symmetry?

Another possibility is that there is statistical disorder, if you don't see plausible packing.

Best wishes,

Randy Read

----
Randy J. Read

> On 28 Sep 2015, at 07:54, Kavyashree Manjunath <[log in to unmask]> wrote:
>
> Dear users,
>
> I am working on a 25kDa protein. The data was processed in
> P6122 space group. According to the Matthews coefficient
> calculated by "cell content analysis" program in CCP4, it is
> a dimer with a probability of 0.98.
>
> -----------------------------------------------------------
> Nmol/asym  Matthews Coeff  %solvent       P(3.53)     P(tot)
> _____________________________________________________________
>  1         4.63            73.44         0.02         0.01
>  2         2.31            46.88         0.97         0.98
>  3         1.54            20.32         0.00         0.00
> -----------------------------------------------------------
> I searched for dimer, but Phaser did not give any solution.
> but gave a solution when searched for a monomer.
>
> One round of refinement with the monomer, resulted in an R
> and Rfree of 0.26 and 0.32 respectively.
>
> Why PHASER is not giving a dimer? What problem could the data
> have in such cases?
>
> Thank you
> Regards
> Kavya
>
>
>
>
>
>
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