Back to Search Start Over

Direct Observation of Chaperone-Induced Changes in a Protein Folding Pathway

Authors :
Ruud G. H. van Leeuwen
Matthew Tyreman
Philipp Bechtluft
Nico Nouwen
Arnold J. M. Driessen
Danuta Tomkiewicz
Harald L. Tepper
Sander J. Tans
Zernike Institute for Advanced Materials
Groningen Biomolecular Sciences and Biotechnology
Molecular Microbiology
Source :
Science, 318(5855), 1458-1461. AMER ASSOC ADVANCEMENT SCIENCE
Publication Year :
2007
Publisher :
American Association for the Advancement of Science (AAAS), 2007.

Abstract

How chaperone interactions affect protein folding pathways is a central problem in biology. With the use of optical tweezers and all-atom molecular dynamics simulations, we studied the effect of chaperone SecB on the folding and unfolding pathways of maltose binding protein (MBP) at the single-molecule level. In the absence of SecB, we find that the MBP polypeptide first collapses into a molten globulelike compacted state and then folds into a stable core structure onto which several α helices are finally wrapped. Interactions with SecB completely prevent stable tertiary contacts in the core structure but have no detectable effect on the folding of the external α helices. It appears that SecB only binds to the extended or molten globulelike structure and retains MBP in this latter state. Thus during MBP translocation, no energy is required to disrupt stable tertiary interactions.

Details

ISSN :
10959203 and 00368075
Volume :
318
Database :
OpenAIRE
Journal :
Science
Accession number :
edsair.doi.dedup.....5c939d3e8004a6d6a57b927b3d0ec346
Full Text :
https://doi.org/10.1126/science.1144972