Re: Masking

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

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naismith@st-andrews.ac.uk wrote:
> 
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> Dear All,
>         Any imaginative solutions?
> We have a dimer in the asu and have good matrices to relate the monomers
> (straight 180 rotn). The starting map is to say the least a little poor.
> 
> Is there a way to harness the averaging to generate a better map from
> which to derive the solvent mask?
> 
> Effectively a single run of maskless averaging.
> 
> I kind of thought by using maprot (mode correlation) and mapmask that it
> should draw a mask around the dimer (proper ncs) which would serve as a
> solvent flattening mask. The resulting mask is dismal and the one from DM
> which I assume is calculated on the unaveraged map is much better. The
> underpining assumption is that the single run averaged map is a better
> place to derive a solvent flattening mask from that the starting map.
> 
> (The ncs mask can be simply made by putting an atom of 40A radius at the
> centroid of the heavy atom position. On our tests this is about as good
> as a monomer mask)
> 
> Any comments/suggestions
> 
> best
> Jim


 dm will generate itts own mask if you ask it to. You must give the
sovent content and ask for NCSMASK NMER 2 ( see "advanced keywords"

Eleanor