Oh- let me try!!
Given two structures each containing the domains A and B,
the angle in question is the further angle through which
domain B of the second structure must be rotated to
superimpose it on domain B of the first structure,
after structure 2 has already been rotated to optimally
superpose domains A.
presumably it matters not if you switch A and B or 1 and 2.
It's the rotation of one domain relative to the other
on going from one structure to the other. Of course a
lot of information is being thrown out like the rotation
axis and any translational component. I understand DynDom
will make a nice graphic with the rotation axis drawn in.
Bernhard Rupp wrote:
> Not that I want to open a can of worms here...
> but could someone explain what is meant
> with 'angle between domains'?
>
> Thx, br
>
> -----Original Message-----
> From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf Of Das,
> Debanu
> Sent: Saturday, July 07, 2007 7:51 PM
> To: [log in to unmask]
> Subject: Re: [ccp4bb] how to convert matrix to angle
>
> Hi,
> You can also use LSQKAB in CCP4 to get the angle between two similar
> domains.
>
> -Debanu.
>
>
> -----Original Message-----
> From: CCP4 bulletin board on behalf of Kay Diederichs
> Sent: Sat 7/7/2007 7:30 AM
> To: [log in to unmask]
> Subject: Re: [ccp4bb] how to convert matrix to angle
>
> Jiamu Du schrieb:
>
>>Dear all:
>>I want to calculate the rotation angle between two similar domains. By
>>using Coot, I can superposr the two domain and get the rotation matrix.
>>But how to convert this matrix to an angle. Is there any program can
>>calculate this ?
>>Thanks.
>>
>
> Jiamu Du,
>
> If you have the rotation matrix
> a11 a12 a13
> a21 a22 a23
> a31 a32 a33
>
> then
>
> (a11 + a22 + a33 - 1) / 2
>
> is the cosine of the angle you're looking for.
>
> HTH,
>
> Kay
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