Would the self rotation map make sense with 4 molecules ?
Jürgen

Sent from my iPad

On Apr 20, 2012, at 2:55, 
"herman.schreu...@sanofi.com<mailto:herman.schreu...@sanofi.com>" 
<herman.schreu...@sanofi.com<mailto:herman.schreu...@sanofi.com>> wrote:

Hi Lisa,

Why are you so sure there are 4 molecules in the ASU? There may only be 3 and 
forcing a fourth molecule is causing lots of clashes. In a similar case, I have 
seen phaser put two molecules right on top of each other when I forced it to 
search for too many molecules.

In your case I would look at the solution (crystal packing) in coot and see 
whether the clashes are due to some loops (or domains) which may move upon 
ligand binding, or whether one of the molecules is at a completely wrong 
position and if you get a good crystal packing (crystal contacts in all 
directions) with fewer molecules. You can also start refinement with fewer 
molecules and see if additional density for missing molecule(s) appears.

Good luck!
Herman

________________________________
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of LISA
Sent: Thursday, April 19, 2012 8:20 AM
To: CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK>
Subject: [ccp4bb] phaser: high z score but no sol

Hi all,

I am trying to solve one structure by molecular replacement with phaser in 
CCP4. This  a complex of a multi-domain domains with small ligand. I have 
structues of this protein in apo state and with other similar ligand.  The 
space group of this crystal is P21. This crystal should have 4 molecules in 
ASU.  I used the full protein as model but did get any sol and LLG is below 
zero. Then each domain were used as the search models in phaser with rotation 
and tranlsation. I can the get high z score (>20), and LLG is raising. It looks 
like I get the right sol, but it  have more 50 clashes.  Why phaser give wrong 
sol with so high z socre? Can anyone give me some suggestion to solve my 
strucutes? Thank you.
Best

Lisa

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