occurring within 3₁₀ helices and at the ends of some classic alpha helices. Type II beta turns, on the other hand, often occur in association with beta-sheet as part of beta-links.

The four types of beta turn are distinguished by the ?, ? angles of residues i+1 and i+2 as shown in the table below giving the typical average values. Glycines are especially common as amino acids with positive ? angles; for prolines