Fig 2. Two examples of helix pairs, which are (A) not significantly different and (B) significantly different.
PDB code, chain identifier and residue numbers are given for each helix. The black residues are at the most disrupted site (see Methods) in each helix pair. rn and rc give the quality of the cylinder fit (see Eq (1)) to the backbone atoms on the N- (red) and C- (blue) terminal sides of the kink site. θ is the angle measured between the two cylinders. ε is the estimated error of the angle measurement, calculated from rn + rc using Eq (4). If θmax − θmin > ε1 + ε2, the confidence intervals do not overlap therefore we consider the angles to be significantly different.