On Fri, Sep 3, 2010 at 4:53 PM, Jin H. Park <jinhp...@mail.med.upenn.edu>wrote:
> I have solved the structure. But, there seems oddly strong density above > histidine residue. > What could this density be? > The protein was in Tris buffer, with NaCl and DTT, and crystallized in > NaSCN with PEG. > (electron density in the pictures is at 1.5 sigma) > In addition to the other possibilities mentioned, a quick Google search indicates that thiocyanate can bind to histidine. If you raise the sigma cutoff much higher, what does it look like? -Nat
