Dear colleagues, I appreciate any help, or any suggestion with my difficult data. Many thanks at least for consideration. I work with datasets at 3.6AA of resolution. Integrated with XDS, scaled with SCALA. After integration and scaling in P1, POINTLESS suggested space group I432:
Space group confidence: 0.95 Laue group confidence: 1.000 Total probability: 0.97 After any longer refinement (more than 20 cycles), there was always a big gap between Rwork and Rfree (0.22 and 0.33), although the structure looks quite good at this resolution. I tried also space group I23, here are my statistics: Data processing (I23 vs I432): Rmerge - 0.124 vs 0.134 high resolution Rmerge - 0.649 vs 0.732 low resolution Rmerge - 0.048 vs 0.037 The gap between Rwork and Rfree was stabilized in I23 using tight NCS restraints: Rwork vs Rfree: I23 withouth NCS: 0.228 vs 0.334 I23 with NCS: 0.249 vs 0.296 I43 : 0.228 vs 0.326 My question is, what would you recommend me to close the gap? Or is this Rfree pointing out a lower real symmetry (I23) than suggested by POINTLESS or PHENIX.XTRIAGE (I432)? I have tried different selection of free reflections in I432 dataset already, but with almost the same results. Many thanks for any response. Petr -- Petr Kolenko [email protected] http://kolda.webz.cz
