Computing axes of symmetry of biological assemblies


Hi all,

Second post about symmetry, this time, we will focus on symmetry detection. This new App computes the axes of symmetry of biological assemblies. Here with 1CHP, just start the App and compute the symmetry:


For large assemblies, automatic symmetry detection may detect several different symmetries. Click on the one that is interesting (typically the one with the higher order and a small RMSD) to visualize the axis. In this example, we use 1B4B which has a dihedral symmetry of order 3:


Another possibility is to provide the symmetry group :


Such a symmetry group has several axes which can be browsed by  expanding the symmetry group. For each axis, the corresponding RMSD is computed. To visualize a particular  axis, click on it in the App interface, and it becomes bold in the viewport. A double click aligns the camera axis with the symmetry axis:


This App supports detection of cyclic and dihedral symmetries of any order, as well as cubic symmetries (tetrahedral, octahedral and icosahedral). Here is an example with an icosahedral capsid 3NQ4:


That’s all for this time! You can get this new App here.

And if you’d like to learn more and connect with other users and developers of SAMSON and SAMSON Elements, join us at SAMSON school 2017.



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