Beta-Alpha-Beta Motif

This motif comprises a beta strand-loop-helix-loop-strand arrangment, with the strands lying parallel and hydrogen-bonded to the helix. The alpha helix packs against the beta strands and thus buries the hydrophobic side chains in these strands. The joining loops regions in the motif can vary in length from one residue to more than 100 residues. 99% of these motifs are right handed.


Handedness of crossover connections in beta sheets.
Richardson JS
Proc Natl Acad Sci U S A73p2619-23(1976 Aug)