Dear members, I would like to have your ideas if there is any way to identify a rotation centre of domain in two different states using CCP4 or other program.
The situation is: the domain of the protein will rotate between two different states (depending on substrate binding) around 8 degree, and it is (nearly) clearly that the domain is rotated around a rotation centrel. So the question is how to identify this "rotation centre" in this 3D model? The ideal is to identify a region of residues in the domain which are most closed to the rotation centre. The tool I am using right now is the "superpose" tool in CCP4 package. The output which I think mightbe uesful is: CENTROID OF "WORKING" MOLECULE : 157.812 152.396 -70.778 CENTROID OF "WORKING" MOLECULE :(fractional) 157.812 152.396 -70.778 CENTROID OF "REFERENCE" MOLECULE: 157.251 151.877 -70.874 CENTROID OF "REFERENCE" MOLECULE:(fractional) 157.251 151.877 -70.874 Distance between CENTROIDS : 0.770 Direction cosines of vector between CENTROIDS: 0.729 0.674 0.124 I would say the “CENTROID" it mentioned above, such as (157.251 151.877 -70.874), is possibly near to the "rotation centre". I would like to have your opinion though. Thank you. King regards, Wenhe