Dear Crystallographers, I recently have been working with a 2.5 Ang SeMet peak wavelength dataset which contains 2 cys's and also a couple of bona fide Cl ions (reasonable b-factor/site is semi-buried/water does not work). In the FFT anomalous difference map using PhiC from the refined model and Dano, I can see the MSE's at ~10 sigma, but no Cl ions, even though Cl should have f" = ~0.3 versus Se's f" = ~4, and no S's in the cys, despite f" = 0.23e. There is really no anomalous peak at all--is it just the smallness of the signal, or are the Se's somehow "swamping out" the other signal? Perhaps the phases are tainted by the presence of semet in the model?
Looking for suggestions, Jacob Keller ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program cel: 773.608.9185 email: j-kell...@northwestern.edu *******************************************
