Dear Kornelius,
a few thoughts that come to my mind:
- Are you sure about the space group P6? For proteins, P6_1, P6_2, ...,
P6_5 are more usual.
- Did you try both hands of the Se-sites? In case of space group P6_n,
you have to invert both the handedness of the sites _and_ of the space
group, resulting in P6_(6-n) (i.e. P6_5 instead of P6_1).
- I wouldn't worry about the mosaicity.
Best regards,
Dirk.
Am 18.10.10 14:03, schrieb Kornelius Zeth:
> Dear all,
>
> we have collected S-SAD data (2x4000 Frames, 0.1 degrees, wedges of 40 Frames, Rf between 3-5% overall) and received a dataset to 2.5 A which is complete with a redundancy of 30-40. Space group is P6 and the AU 120 residues, 6 Mets. Native data are up to 1.9 A Sharp and Phenix both return the expected number of sites and given the phasing power to approx. 3.8 A after HA refinement I was hoping to get some maps which I could use for tracing the structure. However DM, Solomon and Resolve all fail to significantly improve the phases and densities look not as if they can be traced. There is some partial twinning of 15%. What I noticed was that the spot profiles in XDS looked not as the are supposed to, presumably because the mosaicity of the spots are 0.4-0.6 and spot integration may be hampered. Still, merging Rfactors are brilliant.
>
> Any hints + ideas are welcome!
>
> Best wishes
>
> Kornelius
>
> ----------------------------------------------
> Kornelius Zeth
> Max Planck Institute for Developmental Biology
> Dept. Protein Evolution
> Spemannstr. 35
> 72076 Tuebingen, Germany
> [log in to unmask]
> Tel -49 7071 601 323
> Fax -49 7071 601 349
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Dirk Kostrewa
Gene Center Munich, A5.07
Department of Biochemistry
Ludwig-Maximilians-Universität München
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D-81377 Munich
Germany
Phone: +49-89-2180-76845
Fax: +49-89-2180-76999
E-mail: [log in to unmask]
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