A Caltech Library Service

Concerted Complex Assembly and GTPase Activation in the Chloroplast Signal Recognition Particle

Nguyen, Thang X. and Chandrasekar, Sowmya and Neher, Saskia and Walter, Peter and Shan, Shu-ou (2011) Concerted Complex Assembly and GTPase Activation in the Chloroplast Signal Recognition Particle. Biochemistry, 50 (33). pp. 7208-7217. ISSN 0006-2960. PMCID PMC6309729.

[img] PDF - Accepted Version
See Usage Policy.

PDF - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


The universally conserved signal recognition particle (SRP) and SRP receptor (SR) mediate the cotranslational targeting of proteins to cellular membranes. In contrast, a unique chloroplast SRP in green plants is primarily dedicated to the post-translational targeting of light harvesting chlorophyll a/b binding (LHC) proteins. In both pathways, dimerization and activation between the SRP and SR GTPases mediate the delivery of cargo; whether and how the GTPase cycle in each system adapts to its distinct substrate proteins were unclear. Here, we show that interactions at the active site essential for GTPase activation in the chloroplast SRP and SR play key roles in the assembly of the GTPase complex. In contrast to their cytosolic homologues, GTPase activation in the chloroplast SRP–SR complex contributes marginally to the targeting of LHC proteins. These results demonstrate that complex assembly and GTPase activation are highly coupled in the chloroplast SRP and SR and suggest that the chloroplast GTPases may forego the GTPase activation step as a key regulatory point. These features may reflect adaptations of the chloroplast SRP to the delivery of their unique substrate protein.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Shan, Shu-ou0000-0002-6526-1733
Additional Information:© 2011 American Chemical Society. Received: May 12, 2011. Revised: July 21, 2011. Publication Date (Web): July 22, 2011. We thank X. Zhang, N. Pierce, and members of the Shan lab for helpful comments on the manuscript. This work was supported by NIH grant GM078024 to S.S. S.S. was supported by the Beckman Young Investigator award, the Packard and Lucile Award in Science and Engineering, and the Henry Dreyfus Teacher-Scholar Award.
Funding AgencyGrant Number
Arnold and Mabel Beckman FoundationUNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Camille and Henry Dreyfus FoundationUNSPECIFIED
Issue or Number:33
PubMed Central ID:PMC6309729
Record Number:CaltechAUTHORS:20110906-083414953
Persistent URL:
Official Citation:Concerted Complex Assembly and GTPase Activation in the Chloroplast Signal Recognition Particle Thang X. Nguyen, Sowmya Chandrasekar, Saskia Neher, Peter Walter, Shu-ou Shan Biochemistry 2011 50 (33), 7208-7217
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:25224
Deposited By: Ruth Sustaita
Deposited On:06 Sep 2011 15:53
Last Modified:03 Oct 2019 03:04

Repository Staff Only: item control page