Geometry of kinked protein helices from NMR data

► SSNMR orientational restraints from PISEMA are used to find the structure of a kinked alpha helix. ► For use with orientational restraints, a mathematical model of a kinked alpha helix is presented. ► Orientation of helix segments with respect to B determines torsion angles at the residue between. ► Helix rotation and tilt angles from ssNMR used to determine torsion angle pair in kinked helix.