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
>
>
>
>
>
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
|