I also processed with Imosflm and ran Pointless, it was P21. Also it was
indicated by the "Intensity systematic absences" in HKL2000 scale.log file.

Best,
Hubing

On Thu, Jul 21, 2011 at 8:44 PM, <herman.schreu...@sanofi-aventis.com>wrote:

> **
>  Dear Hubing,
>
> One maybe stupid question: Your are sure the space group is P21 and not P2
> or even something else? Did you test other possible space groups? Choosing
> the wrong space group could exactly lead to the results you observe.
>
> Best,
> Herman
>
>
>  ------------------------------
> *From:* CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] *On Behalf Of 
> *Hubing
> Lou
> *Sent:* Thursday, July 21, 2011 6:46 AM
> *To:* CCP4BB@JISCMAIL.AC.UK
> *Subject:* [ccp4bb] Phaser and Molrep gave different solutions
>
> Dear all,
>
> I am stuck in a molecular replacement case and looking for advices.
> I have been working on a protein-DNA complex structure.
> Data was processed by HKL2000 to 2.6Ang and some of the data statistics are
> shown below:
>
> Space group: P21,
> Unit Cell: 54.73, 104.91, 78.40, 90, 100.2, 90
> Redundancy: 2.8 (2.7)
> Completeness: 94.8 (93.1)
> Linear R-fac: 0.051 (0.442)
>
> Data quality was checked by Phenix.xtriage and there's no problem. I then
> prepared a model by Chainsaw. Our protein shares only 30% of sequence
> similarity with the model, but structurally they are in the same group and
> almost identical in apo form. Matthrews Coeff indaced two monomers in AU. I
> then ran Phaser in "automated search" mode and there's a solution with RFZ
> score 4.8, TFZ score 3.8. The electron density map was not bad with DNA
> double helix clearly seen. However Refmac5 couldn't get Rfree lower than
> 50%.
>
> I then changed to MolRep, ran "self rotation function" first then used the
> first 10 peaks for translation search. Again there's a solution but it is
> different from that from Phaser. I attached a picture here. Checking in
> coot, the packing is the same. But, the refinement couldn't get Rfree lower
> than 50%.
>
> I have tried to include NCS, TLS refinement in Refmac, both not working.
> Hope someone out there can help.
> Thanks very much for your time.
>
> Hubing
>
>

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