Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 3 November 2006:
Vol. 314. no. 5800, p. 721
DOI: 10.1126/science.314.5800.721h
Prev | Table of Contents | Next

This Week in Science

Nuclear pore complexes behave like a sieve--they allow small molecules to pass freely but restrict passage of macromolecules (>30 kilodaltons) between the nucleus and cytosol. The so-called FG-rich nucleoporin repeats, which are intrinsically unfolded protein domains that contain short clusters of hydrophobic amino acids separated by hydrophilic spacer regions, are thought to form the barrier, but the functional organization of this barrier has remained a matter of speculation. Frey et al. (p. 815; see the Perspective by Burke and the Perspective by Elbaum) show that these FG-rich repeats occur in an extended conformation and form a noncovalent (and thus reversible) hydrogel. Hydrophobic bridges connecting the individual polypeptide chains and create a three-dimensional sieve-like structure that is crucial for nuclear pore complex function.




To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)