Campus Units

Veterinary Microbiology and Preventive Medicine, Bioinformatics and Computational Biology

Document Type

Article

Publication Version

Published Version

Publication Date

1-15-2013

Journal or Book Title

Molecular Biology of the Cell

Volume

24

Issue

2

First Page

63

Last Page

73

DOI

10.1091/mbc.E12-06-0434

Abstract

During cotranslational protein targeting by the signal recognition particle (SRP), information about signal sequence binding in the SRP's M domain must be effectively communicated to its GTPase domain to turn on its interaction with the SRP receptor (SR) and thus deliver the cargo proteins to the membrane. A universally conserved “fingerloop” lines the signal sequence–binding groove of SRP; the precise role of this fingerloop in protein targeting has remained elusive. In this study, we show that the fingerloop plays important roles in SRP function by helping to induce the SRP into a more active conformation that facilitates multiple steps in the pathway, including efficient recruitment of SR, GTPase activation in the SRP•SR complex, and most significantly, the unloading of cargo onto the target membrane. On the basis of these results and recent structural work, we propose that the fingerloop is the first structural element to detect signal sequence binding; this information is relayed to the linker connecting the SRP's M and G domains and thus activates the SRP and SR for carrying out downstream steps in the pathway.

Comments

This article is from Molecular Biology of the Cell 24 (2013): 63–73, doi:10.1091/mbc.E12-06-0434. Posted with permission.

Rights

This publication is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Copyright Owner

Ariosa et al.

Language

en

File Format

application/pdf

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