[phenixbb] Fo-Fo difference map for non-isomorphous datasets

[Jordan Luke Pederick]

Hi,


I am trying to generate a Fo-Fo difference map for two data sets of the same protein at ~2.3 angstrom resolution. One dataset is native and the other was soaked with a metal ion, so the purpose of the map is for identifying and visualizing peaks that may correspond to a bound metal ion.


These datasets differ by 6 angstroms (~10%) along the A edge - an isomorphous difference map generated in Phenix GUI wasn't useful


As an alternative I was planning to make a real-space Fo-Fo difference map making use of Superpose Maps in Phenix Gui as follows:


Superpose maps would be used to superimpose (Fobs.metal, PHI.metal) and (Fobs.native, PHI.native)

The superimposed maps will be opened in Coot and a difference map generated using "Extensions -> Maps ->  Make a difference map"


There were two things I was unsure about:


Does this seem like a reasonable alternative?

Is scaling of the two datasets required before generating the difference map?


Cheers,

Jordan


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://phenix-online.org/pipermail/phenixbb/attachments/20190309/7a713af1/attachment-0001.htm>