Re: [ccp4bb]: real space difference map?

["Eleanor J. Dodson" <ccp4@ysbl.york.ac.uk>]

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Peter Nollert wrote:
> 
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> Dear all,
> 
> I'd like to compute a difference map, problem is
> that one dataset is in C2221 and the other in P63.
> I guess there's no way to do a difference fourier
> (fo-fo). But it should work in real space.
> How do I calculate a real space difference map?
> 
> Thanks,
> Peter


 You need to calculate maps in both space groups - mask the density for
each 
with a mask from the model:
ncsmask xyzin model.pdb mskout model.msk

then you will need to convert them to the same grid: 
maprot will do that - 
it is a bit complicated but there is an example.

Then mapmask or overlapmap can be used to "add" the maps  applying 
a scale of -1.0 to one

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Eleanor J.Dodson, Chemistry Department, University of York, U.K.
Tel: Home +44 (1904) 42 44 49, work:  +44 (1904) 43 25 65
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