Sorry, I was unclear in my description of the problem.  I have NCS with 4 
heterodimers in the ASU, and a good molecular replacement solution.  So I have 
8 chains total -- A, B, C, and D are identical, and E, F, G, and H are 
identical to each other, but completely different from A, B, C, and D.  I want 
to use the "NCS Phased Refinement" task to generate averaged maps, improve 
phases with density modification, and to restrain refinement so that A, B, C, 
and D are restrained to match each other, and E, F, G, and H are restrained to 
match each other.  In the refmac5 task window, I can see how to set up NCS 
restraints this way, but in the "NCS phased refinement" task window, I don't 
see an equivlent way to define my restraints.  In this window, all I can do is 
make each chain an "NCS unit", and the task fails trying to compare A to E 
(which I don't really want it to do).

Thanks,
Evette

Evette S. Radisky, Ph.D. 
Assistant Professor and Associate Consultant II 
Mayo Clinic Cancer Center
Griffin Cancer Research Building, Rm 310 
4500 San Pablo Road 
Jacksonville, FL 32224 
(904) 953-6372 (office) 
(904) 953-2857 (lab) 



-----Original Message-----
From: Eleanor Dodson [mailto:[EMAIL PROTECTED]
Sent: Thu 2/22/2007 3:42 AM
To: Radisky, Evette S.   Ph.D.
Cc: [email protected]
Subject: Re: [ccp4bb] NCS Phased Refinement
 
Well - the idea of NCS refinement is to restrain the 2 NCS related 
models to be the same so that is problematic if they should be somewhat 
diffeent..
  You can get the matrix using SSM superposition ( see the GUi - 
superpose molecules)
This will match using Secondary structure and give a list of what 
matches what in the two chains.

 You could then set up the restraints carefulyy
eg Chain A res 4 14   res 19 to 35 res 39  to xxx etc matching Chain B 
res 2 to 12   20 36  41 to etc 
You would presumably restrain maybe the main chain but not the side chains

However I am not sure how valuable it would be.
  Eleanor

Radisky, Evette S. Ph.D. wrote:
>
> I have some questions about the "NCS Phased Refinement" task run from 
> ccp4i:
>
> Can one use this task if there are multiple nonidentical chains in the 
> NCS unit (e.g. a heterodimer), and if so, how does one define the NCS 
> units?  I find that the default is to consider each chain as a 
> separate "NCS unit", and the program LSQKAB fails when trying to match 
> residues between non-identical chains.
>
> Thanks,
> Evette
>
> Evette S. Radisky, Ph.D.
> Assistant Professor and Associate Consultant II
> Mayo Clinic Cancer Center
> Griffin Cancer Research Building, Rm 310
> 4500 San Pablo Road
> Jacksonville, FL 32224
> (904) 953-6372 (office)
> (904) 953-2857 (lab)
>

Reply via email to