Re: [ccp4bb] struggling with molecular replacement

2007-07-27 Thread Eleanor Dodson

Does your cell show pseudo symmetry or NCS translations?

Eleanor

Wu, Mousheng wrote:

hi, everyone!
 
I am struggling with my crystal structure in a very big unit cell. my protein is about 16KDa. probably there are about 20 molecules in the asymmetric unit. I tried to use molecular replacement to solve the structure. However, there is only one NMR structure available for me. The second trouble is there are so many molecules in the ASU.  I tried use NMR structure as a model to solve it. MolRep gave me 4 solutions. I refined it first and see the map. The map looks quite reasonable. some parts of the model fit the density and some do not . i tried to trace one molecule first. you can image how hard it is. 
 
Does anyone have such experience?  how can i find so many solutions with NMR model? your suggestions are much appreciated!
 
Mousheng Wu




  


[ccp4bb] struggling with molecular replacement

2007-07-26 Thread Wu, Mousheng
hi, everyone!
 
I am struggling with my crystal structure in a very big unit cell. my protein 
is about 16KDa. probably there are about 20 molecules in the asymmetric unit. I 
tried to use molecular replacement to solve the structure. However, there is 
only one NMR structure available for me. The second trouble is there are so 
many molecules in the ASU.  I tried use NMR structure as a model to solve it. 
MolRep gave me 4 solutions. I refined it first and see the map. The map looks 
quite reasonable. some parts of the model fit the density and some do not . i 
tried to trace one molecule first. you can image how hard it is. 
 
Does anyone have such experience?  how can i find so many solutions with NMR 
model? your suggestions are much appreciated!
 
Mousheng Wu


Re: [ccp4bb] struggling with molecular replacement

2007-07-26 Thread William Scott
It might be worth it to try phaser

Wu, Mousheng wrote:
 hi, everyone!

 I am struggling with my crystal structure in a very big unit cell. my
 protein is about 16KDa. probably there are about 20 molecules in the
 asymmetric unit. I tried to use molecular replacement to solve the
 structure. However, there is only one NMR structure available for me. The
 second trouble is there are so many molecules in the ASU.  I tried use NMR
 structure as a model to solve it. MolRep gave me 4 solutions. I refined it
 first and see the map. The map looks quite reasonable. some parts of the
 model fit the density and some do not . i tried to trace one molecule
 first. you can image how hard it is.

 Does anyone have such experience?  how can i find so many solutions with
 NMR model? your suggestions are much appreciated!

 Mousheng Wu