If you open the structures in Chimera, the "measure rotation" command will report the transformation matrix as well as the screw axis and shift/rotation along/around the screw axis needed. There are also options to that command for actually depicting the screw axis and/or rotation.
www.cgl.ucsf.edu/chimera
www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/midas/measure.html
--Eric
Eric Pettersen
UCSF Computer Graphics Lab
http://www.cgl.ucsf.edu
On Jun 22, 2012, at 4:00 PM, Jeremy Tame wrote:
> Yes, LSQKAB does, but not the equivalent screw axis (which exists by Chasles theorem). I think a screw
> axis may well be the best way to describe the rigid body movement which began the thread. A simple
> distance and angle (2 numbers) are easier to understand, and often of more biological relevance, than
> RT matrices, for example in the case of relative domain motions.
>
> On Jun 20, 2012, at 5:20 PM, Mark J van Raaij wrote:
>
>> LSQKAB ("superpose" in CCP4i GUI) also outputs in its log-file the translation parameters and rotation matrix it used to superpose the structure.
>
