First thing to check - is there any anomalous scatterer peak in the density? Easy to do an anom diff map from GUI2 - choose REFMAC and add - do anom diff fourier, then follow with a diff peak search in COOT . Eleanor
On 14 June 2017 at 18:04, Sanishvili, Ruslan <rsanishv...@anl.gov> wrote: > Difficult to guess from what is visible of the protein but is this density > on a two-fold axis? > > Or, it could be Slimer the ghost... > > Cheers, > > Nukri > > > Ruslan Sanishvili (Nukri), Ph.D. > Macromolecular Crystallographer > GM/CA@APS > X-ray Science Division, ANL > 9700 S. Cass Ave. > Lemont, IL 60439 > > Tel: (630)252-0665 <(630)%20252-0665> > Fax: (630)252-0667 <(630)%20252-0667> > rsanishv...@anl.gov > > > > ------------------------------ > *From:* CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of Nick > Thomas <nicky.alp...@gmail.com> > *Sent:* Wednesday, June 14, 2017 11:39 AM > *To:* CCP4BB@JISCMAIL.AC.UK > *Subject:* [ccp4bb] Unknown Ligand Density > > Dear CCP4bb, > > I am refining a structure and have come across strong electron density for > an unknown ligand (image attached). Would someone be able to identify > this unknown ligand that somehow was co-purified with the protein. > > > The electron density shape does not match anything included in the > crystallization conditions. > > > The crystallization condition is > 0.1M MES monohydrate, pH 6.5, 1.6 M Magnesium sulphate heptahydrate >
