I would run DM first to extend the experimental phases to the limit of
your resolution..
Then if you run REFMAC to refine your MR model, using the experimental
phases as part of the input the output phases from REFMAC will include
contributions from both the MR and the DM/experimental phasing. This will
be weighted according to the FOMs for the refined model R factors and the
experimental ABCDs
( But make sure your MR and experimental phases are on the same origin and
hand! Easiuest way to do this is to get a mtz file with the Model phases
alone, "CAD"ed with the experimental phases then run phasematch - a
reflection utility. This tells you if you need to shift the origin for
either MR or exptl phases and applies the correction..)
Of course the part of the map with the model phases will look better, and
at 3.1A you will have trouble rebuilding the remaining stuff but good luck!
Eleanor
On Tue, 12 Jul 2011 21:15:24 -0400, "Bosch, Juergen" <[log in to unmask]>
wrote:
> http://www.globalphasing.com/sharp/
> or you could extend your phases using DM if you have more than one
> molecule in the asu.
> I'm sure there is also a way to convince solve/resolve to do what you
want.
> If you see enough in your map, just build a backbone model and use that
to
> generate a crude mask for DM (in case you can apply NCS averaging).
>
> Jürgen
>
> On Jul 12, 2011, at 9:08 PM, Jiamu Du wrote:
>
> Dear All,
> I am now working on a low resolution phase determination (around 3.3 A
> with Se anomalous signal around 3.8 A).
> I can find the Se site and get the phase, but the density map is not so
> good.
> Some part of the protein (about 1/3) has a homologue model which is also
> can be found using Phaser. The homologue region has a good map while
other
> region only show a poor map.
> I think the combination of experimental phase and MR phase might improve
> the map. Is there anybody can help find which program can work on this?
>
> Thanks.
> --
> Jiamu Du, Ph.D.
> Postdoctoral Research Fellow
> Laboratory of Structural Biology
> Memorial Sloan-Kettering Cancer Center
> RRL 269, 430 E 67th Street
> New York, NY, 10021
> E-mail: [log in to unmask]<mailto:[log in to unmask]>
> Tel: (217) - 417 - 9897
>
>
> ......................
> Jürgen Bosch
> Johns Hopkins Bloomberg School of Public Health
> Department of Biochemistry & Molecular Biology
> Johns Hopkins Malaria Research Institute
> 615 North Wolfe Street, W8708
> Baltimore, MD 21205
> Phone: +1-410-614-4742
> Lab: +1-410-614-4894
> Fax: +1-410-955-3655
> http://web.mac.com/bosch_lab/
|