Dear Armando,
Is 1.9Å really the diffraction limit of your crystals, or do they diffract further and is 1.9Å just a convenient resolution cutoff? In the latter case you might be looking at truncation effects.
Best,
Herman
-----Ursprüngliche Nachricht-----
Von: CCP4 bulletin board [mailto:[log in to unmask]] Im Auftrag von Armando Albert
Gesendet: Freitag, 18. Juli 2014 18:04
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Betreff: [ccp4bb] Negative electron density in the Fo-Fc map at the binding site
Dear all,
I am screening a small library of ligands against my protein crystals. Following a soaking with different ligands, I collect datasets to 1.9A resolution and refine them against an empty model without any problem.
What is the meaning of a rather large negative electron density in the Fo-Fc map at the binding site?. Could it be related to an incorrect bulk solvent model?
Thank you in advance
Armando
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