Intriguingly, in a combined NMR and molecular dynamics study, Camilloni and co-workers proposed that R55 provides a stabilizing electric field that aligns with the electric dipole of the peptidyl carbonyl group as the pseudo-peptide bond rotates through the cis/trans transition state. This 'electrostatic handle' was suggested to drive the rotation to occur only via positive peptide w-angles by reducing the activation energy when the carbonyl dipole is aligned with the R55 electric field, and increasing it when nonaligned.