Figure 2.

Structure of a steric zipper formed by the short peptide GNNQQNY. (a) Side view and (b) top view of the pair of β-sheets are shown. In (a), the backbone of each β-strand is represented as an arrow, and the side chains protruding from the backbones are shown as ball-and-stick models. In (b), two GNNQQNY molecules are shown as stick models, and their interface demonstrates the shape complementarity of the asparagine and glutamine side chains. Reprinted from [19] with permission. Copyright (2005) Springer Nature.