On Monday, 14 May 2018 10:39:32 Daniel Garcia wrote: > Dear all, > > I am currently refining a structure and found a intriguing electron density > at the protein surface (pictures attached, the Fo-Fc map is contoured at > >3.5 sigma). My first candidates were molecules from my protein prep or > crystallisation buffer, but none of them seem to fit well. I can observe > that the ligand is nearby the side chains of a tyrosine, a lysine, a > threonine and a glutamate residue, and it is close to the carbonyl oxygens > of the protein backbone of a nearby loop. The shape of this density is not > pyramidal, but it is not planar either. > > Do you have any suggestions to solve this density based on your own > experience? My crystallisation buffer contains tartrate, ammonium sulphate, > and CHES, and my protein is in Tris buffer containing DTT and sodium > chloride.
DMSO? > > Best regards, > > -- Ethan A Merritt, Dept of Biochemistry Biomolecular Structure Center, K-428 Health Sciences Bldg MS 357742, University of Washington, Seattle 98195-7742