Hi Careina Not sure what you mean when you say "despite unit cell dimensions being off". What are the cells for the monoclinic & orthorhombic indexings? The SRF cannot always tell you if there's higher symmetry because NCS axes may align with crystallographic ones giving pseudo-translational NCS and confusing the interpretation. That's why it's important to check the native Patterson for any peaks that could be due to translational NCS. Can we see the kappa=180 section of the SRF? (I don't have 100% faith in peak searches!).
The SRF log file you posted was done in PG222, what does the plot of the kappa=180 section in PG2 look like? We need a bit more information! Cheers -- Ian On Mon, Jun 6, 2011 at 8:57 AM, Careina Edgooms <careinaedgo...@yahoo.com>wrote: > Dear Ian > > Thank you for your help. > It is 46% solvent content for 2 monomers when I process in P21 space group. > Because there does appear to be NCS, I guess it is accurate to say there are > 2 monomers? Does the SRF indicate that there is perhaps a higher symmetry? I > wonder if I should attempt to process in P222 or P212121 despite unit cell > dimensions being off? When I do try solve 2 monomers in asymmetric unit in > P21 I see many clashes although it refines with satisfactory R factors. > > Thanks again for your help > Careina > > > ------------------------------ > *From:* Ian Tickle <ianj...@gmail.com> > *To:* Careina Edgooms <careinaedgo...@yahoo.com> > *Cc:* CCP4BB@jiscmail.ac.uk > *Sent:* Sat, June 4, 2011 3:03:42 PM > *Subject:* Re: [ccp4bb] self rotation function > > > Hi Careina > > 30% of the origin peak is fairly respectable. You could probably make it > higher by varying the high res cutoff. You have 2 Ang: it may be that the > NCS doesn't extend to that resolution, so making it a bit lower might > improve the signal/noise ratio. It would be nice to see the plot of the > kappa=180 section, but from the log file it's clear you have a lot of NCS > 2-folds in the ab plane (kappa=180, omega=90), so my guess would be a 222 > tetramer aligned with an NCS 2-fold parallel to the c axis. If so this > should give you an translational NCS peak somewhere in the z=1/2 Harker > section of the native Patterson. From the solvent content how many > molecules in the a.u. do you expect? > > Cheers > > -- Ian > > On Fri, Jun 3, 2011 at 2:01 PM, Careina Edgooms > <careinaedgo...@yahoo.com>wrote: > >> Dear ccp4 members >> >> I have question about how to interpret polarrfn log. I wish to know if my >> crystal display NCS. I am not sure how to interpret the file. I see it have >> two peak, one is origin and the other is not that high to me. I have attach >> copy of the file. If someone could assist me to understand the file it would >> be appreciated. >> >> best >> Careina >> > >
