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Hi John, There are different reasons for R-free to be high, one of the possibility might be overfitting the data, 1. try to change the sterochemistry weight in the refinement (increase or decrease) 2. delete the fragments which are doubtful. other alternates might be, (1) Check your data processing statistics such as Rmerge, completeness all resolution bins to see any strange behavior. (2) check the molecular replacement solution, from PHASER. Correct solution might be rejected due to packing criteria. So you can try different combinations like monomer or dimer as probe for the molecular replacement to avoid the rejection of correct solution. Check for alternative solution related by translation to your current solution from the list. hope this might help vk --- John Luz <[EMAIL PROTECTED]> wrote: ,> *** For details on how to be removed from this list > visit the *** > *** CCP4 home page http://www.ccp4.ac.uk > *** > > > HI All > > I have an MR solution from phaser which gives four > molecules/au. (MR model ~50% identical) > > The space group is P21, 52.2 177.9 87.6 = abc with a > beta angle of 105.5. Solvent content ~40%. > > The data is good to about 2.5A. > > The intial maps were not as good as would be > expected from the data but were easily > interpretable. After three rounds of model building > the Rfree is stuck at 41% and the R is 33%. There > is a significant amount of disorder in one domain > but about 75% of the model is built in. The maps > look OK but not great. After reviewing the maps, > there are still areas that, with care, could be > built but the density there is not so well-defined. > However, it seems fishy that the Rs are still so > high. > > The truncate log file does not seem to indicate > twinning. > > Any ideas/comments much appreciated. > > Thanks > > jl > > > > > Kabaleeswaran Venkataraman Arise, Awake and stop not until goal is Reached - Swami Vivekanand __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
