Hi Cat, If your pseudo-centering actually leads to significant change in your cumulative intensity distribution, you might have a convincing explanation as to why the R-values would remain on the high side. I had a pseudo-body centered case a long time ago (https://doi.org/10.1107/s0907444906031519) and there the R-values remained a lot higher.
HTH, Esko On 29 May 2024, at 15:48, Catherine Back <0000d42dc456258a-dmarc-requ...@jiscmail.ac.uk> wrote: Hi, I have collected data for a protein which solved easily to 1.6 Å using MR. However, during data analysis and refinement it clearly has translational NCS. According to Xtriage on Phenix: Frac. coord.: 0.072, -0.498, 0.5 Distance to origin: 68.798 Height relative to origin: 51.479% p-value (height): 5.577e-05 Wilson value and L-test suggests no twinning. It solved using Molrep in ccp4i2. P2 21 21. All stats look good, but even after refinement (not fully and completely finalised yet) R= 0.24 and Rfree=0.27. Also, it appears the 2 molecules in the AU have swapped a helix with their respective symmetry partners. I'm pretty sure I now have the correct space group, and tried various others with much less success. 1. Will these Rfactors be 'good'/low enough to publish for a dataset at 1.6Å? 2. Should I be doing anything else during structure solving to alleviate the effects of tNCS? (I did try using Phaser to solve the structure, but the stats were much worse and even though 'tNCS is present correction factors were not applied'. I'm not sure why. Many thanks, Cat Dr Catherine R. Back (she/her) Senior Post-doctoral Research Associate School of Biochemistry University of Bristol UK ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
