I would contact some MassSpec people and ask if they could find out the mass of
your mystery ligand. I would also carefully look at the neighboring protein. It
might be an alternate conformation of a partially disordered loop. Finally, I
would check literature to see if a natural ligand/cofactor of your protein
would fit. However, your ligand seems to be bound in a crystal contact so it
may be an artifact.
Von: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] Im Auftrag von Nick
Gesendet: Mittwoch, 14. Juni 2017 18:40
Betreff: [ccp4bb] Unknown Ligand Density
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
The crystallization condition is
0.1M MES monohydrate, pH 6.5, 1.6 M Magnesium sulphate heptahydrate