A Perspective on the (Rise and Fall of) Protein ß-Turns.

ABSTRACT

The ß-turn is the third defined secondary structure after the α-helix and the ß-sheet. The ß-turns were described more than 50 years ago and account for more than 20% of protein residues. Nonetheless, they are often overlooked or even misunderstood. This poor knowledge of these local protein conformations is due to various factors, causes that I discuss here. For example, confusion still exists about the assignment of these local protein structures, their overlaps with other structures, the potential absence of a stabilizing hydrogen bond, the numerous types of ß-turns and the software's difficulty in assigning or visualizing them. I also propose some ideas to potentially/partially remedy this and present why ß-turns can still be helpful, even in the AlphaFold 2 era.