Design of a heterospecific, tetrameric, 21-residue miniprotein with mixed alpha/beta structure

Structure. 2005 Feb;13(2):225-34. doi: 10.1016/j.str.2004.12.009.


The study of short, autonomously folding peptides, or "miniproteins," is important for advancing our understanding of protein stability and folding specificity. Although many examples of synthetic alpha-helical structures are known, relatively few mixed alpha/beta structures have been successfully designed. Only one mixed-secondary structure oligomer, an alpha/beta homotetramer, has been reported thus far. In this report, we use structural analysis and computational design to convert this homotetramer into the smallest known alpha/beta-heterotetramer. Computational screening of many possible sequence/structure combinations led efficiently to the design of short, 21-residue peptides that fold cooperatively and autonomously into a specific complex in solution. A 1.95 A crystal structure reveals how steric complementarity and charge patterning encode heterospecificity. The first- and second-generation heterotetrameric miniproteins described here will be useful as simple models for the analysis of protein-protein interaction specificity and as structural platforms for the further elaboration of folding and function.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Computational Biology*
  • Crystallization
  • Crystallography, X-Ray
  • Molecular Sequence Data
  • Mutation / genetics
  • Peptides / chemistry*
  • Peptides / genetics
  • Protein Folding
  • Protein Structure, Secondary


  • Peptides

Associated data

  • PDB/1XOF