[ccp4bb]: averaging structures

[<rams@poori.biochem.uiowa.edu>]

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


Hello All,

I remember this question being asked in a different context - but I did 
not find the answer so here I go again!

I managed to solve a structure using an NMR ensamble and Beast.  I also 
manage to do the same with AMoRe (the Navaza version - the ccp4 version 
does not seem to do it).  I cannot seem to get the structure with one 
model - so thats fine.  I think the solution is correct as it is 
significantly higher in cc than the others.  Packs well.  The space group 
could be p4x2x2 and I get clear values for x - i.e., I can solve the 
structure only in p43212. So, I am happy :-)

Trouble starts when I begin to refine.  I have tried refining with refmac 
and one model.  CNS with one model.  dm after rigid body refinement etc.. 
and several starting models.  In every case, I end up producing maps that 
are good and bad (I can always see some side chains that show up clearly 
after throwing in a poly Ser model).  So, that gives me confidence.

My data is good only to 2.2A resolution (crappy data to 1.8 available).  I 
have tried warp and resolve too.. Nothing seems to do well.  So, what I 
want to do is simply calculate phases from each one of the NMR models  
and average then "warp style" and calculate maps.  Is there a nice way to 
do it ?

Thanks.

Rams.


-- 
S. Ramaswamy
Department of Biochemistry.
University of Iowa.