A conserved spider silk domain acts as a molecular switch that controls fibre assembly

Franz Hagn, Lukas Eisoldt, John G. Hardy, Charlotte Vendrely, Murray Coles, Thomas Scheibel, Horst Kessler*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

272 Citations (Scopus)
384 Downloads (Pure)

Abstract

A huge variety of proteins are able to form fibrillar structures(1), especially at high protein concentrations. Hence, it is surprising that spider silk proteins can be stored in a soluble form at high concentrations and transformed into extremely stable fibres on demand(2,3). Silk proteins are reminiscent of amphiphilic block copolymers containing stretches of polyalanine and glycine-rich polar elements forming a repetitive core flanked by highly conserved non-repetitive amino-terminal(4,5) and carboxy-terminal(6) domains. The N-terminal domain comprises a secretion signal, but further functions remain unassigned. The C-terminal domain was implicated in the control of solubility and fibre formation(7) initiated by changes in ionic composition(8,9) and mechanical stimuli known to align the repetitive sequence elements and promote beta-sheet formation(10-14). However, despite recent structural data(15), little is known about this remarkable behaviour in molecular detail. Here we present the solution structure of the C-terminal domain of a spider dragline silk protein and provide evidence that the structural state of this domain is essential for controlled switching between the storage and assembly forms of silk proteins. In addition, the C-terminal domain also has a role in the alignment of secondary structural features formed by the repetitive elements in the backbone of spider silk proteins, which is known to be important for the mechanical properties of the fibre.

Original languageEnglish
Pages (from-to)239-242
Number of pages4
JournalNature
Volume465
Issue number7295
DOIs
Publication statusPublished - 13 May 2010

Keywords

  • TERMINAL DOMAIN
  • EXCHANGE-RATES
  • PROTEINS
  • DRAGLINE
  • ASSIGNMENT
  • STABILITY
  • MECHANISM
  • SEQUENCE
  • SHIFT
  • supramolecular chemistry
  • protein assembly

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Biomaterials

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