Simulation of Top7-CFr: a transient helix extension guides folding

Proc Natl Acad Sci U S A. 2008 Jun 10;105(23):8004-7. doi: 10.1073/pnas.0708411105. Epub 2008 Apr 11.

Abstract

Protein structures often feature beta-sheets in which adjacent beta-strands have large sequence separation. How the folding process orchestrates the formation and correct arrangement of these strands is not comprehensively understood. Particularly challenging are proteins in which beta-strands at the N and C termini are neighbors in a beta-sheet. The N-terminal beta-strand is synthesized early on, but it can not bind to the C terminus before the chain is fully synthesized. During this time, there is a danger that the beta-strand at the N terminus interacts with nearby molecules, leading to potentially harmful aggregates of incompletely folded proteins. Simulations of the C-terminal fragment of Top7 show that this risk of misfolding and aggregation can be avoided by a "caching" mechanism that relies on the "chameleon" behavior of certain segments.

Publication types

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

MeSH terms

  • Computer Simulation*
  • Peptide Fragments / chemistry*
  • Protein Folding*
  • Protein Structure, Secondary
  • Proteins / chemistry*
  • Proteins / metabolism*
  • Temperature
  • Thermodynamics

Substances

  • Peptide Fragments
  • Proteins