First Observation of Two Consecutive γ Turns in a Crystalline Linear Dipeptide

Which way to turn? For the very first time, a linear dipeptide has been shown to accommodate two consecutive γ turns in the solid state. An aminocyclopropane carboxylic acid has overridden the tendency of proline to induce a β-turn conformation in Pro-Xaa dipeptides (see X-ray crystal structure; blue: N, red: O, dashed lines show H bonds).