Answer is NO to difficulty; H32 is no easier or harder in principal than
any other SG..
However do you have a NCS translation? or twinning?
Is your model likely to be an oligomer?
Eleanor
Shane Atwell wrote:
> I'm struggling with a molecular replacement. Its a kinase, for which we
> have the structure in another spacegroup with a different ligand. The 3A
> data processes in either C2 with ~12mol/asu or R3 with 8 or R32 with 4,
> the later having higher but reasonable Rmerges. Low shells look good
> (around 7%) The crystals themselves look classically rhombohedral. I
> think R32 is the likely spacegroup.
>
> Molecular replacement with either the entire kinase domain or the
> C-terminal subdomain in C2, R3 and R32 has so far failed in phaser,
> molrep and epmr. This is using the data in the hexagonal treatment
> (H32). I've used phaser extensively, attempting to turn off clustering,
> take top 1000 hits, and brute force rot/tran.
>
> My questions are the following:
>
> Does the hexagonal (H32) treatment of the R32 data introduce extra NCS
> translational symmetries that could interfere with the MR? I don't think
> this is the case, the H32 treatment should only introduce extra
> crystallographic symmetries. (There still could be NCS translations
> though since I have at least 4 molecules.)
>
> Is there a molecular replacement package or setting that will do the MR
> in true R32 and would this help?
>
> Any other suggestions?
>
> Thanks in advance.
>
> Shane Atwell
>
>
>
>
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