Dear Shanti Pal, did you use ethylene glycol as cryoprotectant? It may even be there in small amounts in your PEG400 solution. As Nicholas and Tony have said, this could be noise (or could be distorted due to noise) as it's on a 2-fold axis. From those pictures, it looks to me like one molecule of ethylene glycol (Coot -> Get Monomer -> EDO). Don't forget to drop the occupancy to 0.5, though!
Best Isaac On 23 June 2014 13:17, Shanti Pal Gangwar <gangwar...@gmail.com> wrote: > Dear All > > I have solved a structure of my protein at 3.0 A. The crystallization > condition is consisting of PEG400, NaCl, MgCl2 and Sodium citrate. The > protein was purified in HEPES buffer. > I can see an unidentified electron density blob in coot and I am not able > to figure out what it could be? > > I have attached the snapshot of that blob with this mail. I request > everyone to please help me in identification of this blob. > > Thanking you in advance. > > > > > > > > Shanti Pal > > > ******************** > Best regards > Shanti Pal Gangwar, Ph.D > School of Life Sciences > Jawaharlal Nehru University > New Delhi-110067 > India > Email:gangwar...@gmail.com > > >
