Hi Appu,
you start already with a fixed spacegroup (scaled merged data) according
to your pointless log. So you can't get another possible solution from
pointless.
Cheers
Am 22.04.2015 um 22:28 schrieb Appu kumar:
> Dear CCP4 Member,
> I seek your advice on the refinement issues at the low resolution 4A. I
> am trying to refine a membrane protein structure after getting the
> phases from MR using the PHASER. The soluble domain structure which
> comprises of 40% of protein has been used as template (sequence identity
> 80%) in MR search . The PHASER gave a good solution having TFZ value of
> about 14.3. I have then created the polyA model for the transmembrane
> domain from distant homolog which share 30% sequence identity for TM
> region and try to find the phases for whole TM domain keeping the
> soluble domain fixed. I got lucky in getting the phases for the whole
> protein using the PHASER (TFZ=17.6) but the during the refinement, Rwork
> and Rfree got stalled at the 41 and 44 respectively after several cycle
> of the refinement in both refmac and phenix. I checked the spacegroup
> with pointless and it suggests C2221. I have attached the pointless and
> phenix.xtriage run file with this mail for your evaluation.
> Phenix.xtriage suggests no major pathologies with the data except the
> mild psuedomerohedral twining. There are two molecules of protein in
> ASU. Evaluation of the density maps, suggest reasonable map for the most
> of protein part. I am wondering why Rwork and Rfree are not coming down
> despite of the good MR solution and what i am doing wrong with
> refinement and if there is some pathologies associated with the data
> which needs to be answered before heading to refinement.
>
> Thanks for your help in advance.
>
> Appu
>
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