> interpretable electron density map is obtained to which most of your
protein model can be fitted properly. The primary numeric indication for
that are your R-factors. 

 

Minor comment: The measure for the fit of the *model (density) to the
electron density* is actually a local real space correlation coefficient or
a local real space R value, not the global reciprocal space R-values (not a
*factor* in the mathematical sense, nor a factor for anything else). The
overall linear residual between model structure factor amplitudes Fc and
observed amplitudes Fo (aka R(F)-value) is a global reciprocal space
measure, which can be affected by many other contributions causing the
misfit between Fo and Fc data, in addition to bad model, as already noted
below.  

 

Ø  The high values you have suggest that either something is wrong with your
space group, twinning, etc. as Eleanor suggested, or your space group and MR
solution may be still correct but for a search model of poor similarity with
your crystal structure. Even in the later case, at this resolution it is
going to be very challenging to build and refine a structure to reasonable
R-factors starting from a poor model.

 

Hay

 

 

========================================
Hay Dvir               Ph. D.
Head           Technion Center for Structural Biology
Technion    Haifa 3200003, Israel
Tel:                       +(972)-77-887-1901
Fax:                      +(972)-77-887-1935
E-mail                   hd...@technion.ac.il

Website                http://tcsb.technion.ac.il/Hay-Dvir
========================================



On Feb 4, 2014, at 11:36 AM, Shanti Pal Gangwar wrote:





Dear All

I have solved one structure by MR. The data data quality was poor so the
Rmerge was high. The resolution of the data is 3.3 Angstrom.The refinement
statistics are also very poor Rw/Rf= 40/42 %. After many efforts we are not
able to get reasonable Rw/Rf.

 

My question is "can it be claimed that we have solved the structure?" 



Thanks in advance





-- 
********************
regards
Shanti Pal Gangwar
School of Life Sciences
Jawaharlal Nehru University
New Delhi-110067
India
Email:gangwar...@gmail.com <mailto:email%3agangwar...@gmail.com> 



 

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