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.
Proc Natl Acad Sci U S A73p2619-23(1976 Aug)
J Mol Biol109p235-50(1977 Jan 15)
Sternberg MJ, Thornton JM
J Mol Biol105p367-82(1976 Aug 15)