Hi Andrew, If there is no *protein* model built into this region of the map, then it will be modelled by the bulk solvent correction - therefore, the negative peaks are telling you that the mean electron density there is lower than in the bulk solvent. Probably. Joe
> Hello everyone I have a question for the experts. > > I am in the final stages of refining my model > placing waters and whatnot. However when I refine > my model against the pure scalepack output, I see > some rather signifigant negative difference > density peaks (3sigma) in a marginally important > region of the protein. The strange thing is that > there is no model built into this region. How can > there be negative difference density when there > is no model built there? It is obviously not a > weighting problem because the structure factors > are directly from the raw reflection list. Has > anyone else ecperienced this phenomenon and what > if any actions would you suggest. I have attached > also a screenshot. Thanks for your advice > everyone I have learned so much from reading this > BB everyday. > > > Drew > > ------------------------------------------------------------ > This email message, including any attachments, is for the sole use of the > intended recipient(s) and may contain information that is proprietary, > confidential, and exempt from disclosure under applicable law. Any > unauthorized review, use, disclosure, or distribution is prohibited. If > you have received this email in error please notify the sender by return > email and delete the original message. Please note, the recipient should > check this email and any attachments for the presence of viruses. The > organization accepts no liability for any damage caused by any virus > transmitted by this email. > ================================= >
