Re: [ccp4bb]: Structure Resolution!

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

***  For details on how to be removed from this list visit the  ***
***          CCP4 home page http://www.ccp4.ac.uk         ***

Rajeswari Edayathumangalam wrote:
> 
> ***  For details on how to be removed from this list visit the  ***
> ***          CCP4 home page http://www.ccp4.ac.uk         ***
> 
> Hi Everyone,
> I followed a discussion a while ago as to whether (and at what
> resolution) should one cut off their data. I am still somewhat confused.
> Following the discussion, I revisited some of my data and I find that
> the data is good to almost 2.6 A, while I am using 2.8 A as my cut-off
> based on the criteria of I/sigma > 2.0 and R-symm < 40.0 % , the
> standards used in our lab.
> I am already past 3 rounds of refinement and manual rebuilding using
> data to 2.8A. Can I, at this point, suddenly take data all the way to
> 2.6 A and proceed with refinement ? Or, should I restart the entire
> refinement from the very beginning ? Is it legitimate to refine data to
> a higher resolution and finally report to a lower resolution ?


 Certainly that is OK -  many mant MR structures take a model refined at
one resolution straight int o refinement at a diff resolution..

> Also, I am not clear as to what kind of differences I would see between
> maps calculated with data upto 2.6A and 2.8A.


You will just have to look and see. It is a good idea to set the
occupancies for some test residue - preferably something big - too 0.00
then see how well it comes back in the two maps.

Eleanor