Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 101, Issue 20, Pages 7583-7588Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.0402398101
Keywords
-
Categories
Ask authors/readers for more resources
It is known that the DnaK and Trigger Factor (TF) chaperones cooperate in the folding of newly synthesized cytosolic proteins in Escherichia coli. We recently showed that despite a very narrow temperature range of growth and high levels of aggregated cytosolic proteins, E. coli can tolerate deletion of both chaperones, suggesting that other chaperones might be involved in this process. Here, we show that the secretion-dedicated chaperone SecB efficiently suppresses both the temperature sensitivity and the aggregation-prone phenotypes of a strain lacking both TF and DnaK. SecB suppression is independent of a productive interaction with the SecA subunit of the translocon. Furthermore, in vitro cross-linking experiments demonstrate that SecB can interact both co- and posttranslationally with short nascent chains of both secretory and cytosolic proteins. Finally, we show that such co-translational substrate recognition by SecB is greatly suppressed in the presence of ribosome-bound TF, but not by DnaK. Taken together, our data demonstrate that SecB acts as a bona fide generalized chaperone.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available