biotite.structure.dihedral_backbone¶

biotite.structure.
dihedral_backbone
(atom_array)[source]¶ Measure the characteristic backbone dihedral angles of a structure.
 Parameters
 atom_array: AtomArray or AtomArrayStack
The protein structure. A complete backbone, without gaps, is required here. Chain transitions are allowed, the angles at the transition are NaN. The order of the backbone atoms for each residue must be (N, CA, C).
 Returns
 phi, psi, omegandarray
An array containing the 3 backbone dihedral angles for every CA. ‘phi’ is not defined at the Nterminus, ‘psi’ and ‘omega’ are not defined at the Cterminus. In these places the arrays have NaN values. If an
AtomArrayStack
is given, the output angles are 2dimensional, the first dimension corresponds to the model number.
 Raises
 BadStructureError
If the amount of backbone atoms is not equal to amount of residues times 3 (for N, CA and C).
See also
Examples
>>> phi, psi, omega = dihedral_backbone(atom_array) >>> print(np.stack([np.rad2deg(phi), np.rad2deg(psi)]).T) [[ nan 56.145] [ 43.980 51.309] [ 66.466 30.898] [ 65.219 45.945] [ 64.747 30.346] [ 73.136 43.425] [ 64.882 43.255] [ 59.509 25.698] [ 77.989 8.823] [ 110.784 8.079] [ 55.244 124.371] [ 57.983 28.766] [ 81.834 19.125] [124.057 13.401] [ 67.931 25.218] [143.952 131.297] [ 70.100 160.068] [ 69.484 145.669] [ 77.264 124.223] [ 78.100 nan]]