Beta-Hairpin

This is bovine pancreatic trypsin inhibitor, a small protein with a long, and twisted beta-hairpin in gold. The 2 beta-strands each have 8 amino acid residues. The beta-hairpin is flanked by two short alpha-helices

Since the beta-strands are longer than average, the twist completely reverses the sidedness of the strands.

Parkin, S.,  Rupp, B.,  Hope, H. Structure of bovine pancreatic trypsin inhibitor at 125 K: Acta Crystallogr D Biol Crystallogr v52 pp.18-29, 1996 (PubMed)

1bpi (PDB)