Or give it to arp/warp, either with the current model to improve or with phases
from the current model to build new model?

Phoebe A. Rice wrote:
What happens if you solvent-flatten/flip/massage that map, but tell the 
software the solvent content much lower than
what you think it is now? Maybe you'll find another copy of the molecule?

------------------------------------------------------------------------------------------------------------------------
*From:* CCP4 bulletin board [[email protected]] on behalf of Andrey 
Nascimento [[email protected]]
*Sent:* Friday, March 15, 2013 1:39 PM
*To:* [email protected]
*Subject:* [ccp4bb] Strange density in solvent channel and high Rfree

*Dear all,*

*I have collected a good quality dataset of a protein with 64% of solvent in P 
2 21 21 space group at 1.7A resolution
with good statistical parameters (values for last shell: Rmerge=0.202; 
I/Isig.=4.4; Complet.=93% Redun.=2.4, the overall
values are better than last shell). The structure solution with molecular 
replacement goes well, the map quality at the
protein chain is very good, but in the final of refinement, after addition of a 
lot of waters and other solvent
molecules, TLS refinement, etc. ... the Rfree is a quite high yet, considering 
this resolution (1.77A).(Rfree= 0.29966
and Rfactor= 0.25534). Moreover, I reprocess the data in a lower symmetry space 
group (P21), but I got the same problem,
and I tried all possible space groups for P222, but with other screw axis I can 
not even solve the structure.*

*A strange thing in the structure are the large solvent channels with a lot of 
electron density positive peaks!? I
usually did not see too many peaks in the solvent channel like this. This peaks 
are the only reason for these high R's
in refinement that I can find. But, why are there too many peaks in the solvent 
channel???*

*I put a .pdf file (ccp4bb_maps.pdf) with some more information and map figures 
in this link:
https://dl.dropbox.com/u/16221126/ccp4bb_maps.pdf*

*
*

*Do someone have an explanation or solution for this?*

**

*Cheers,*

*Andrey*

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