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SecYEG activates GTPases to drive the completion of cotranslational protein targeting

Signal recognition particle (SRP) and its receptor (SR) comprise a highly conserved cellular machine that cotranslationally targets proteins to a protein-conducting channel, the bacterial SecYEG or eukaryotic Sec61p complex, at the target membrane. Whether SecYEG is a passive recipient of the transl...

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Detalles Bibliográficos
Autores principales: Akopian, David, Dalal, Kush, Shen, Kuang, Duong, Franck, Shan, Shu-ou
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3575545/
https://www.ncbi.nlm.nih.gov/pubmed/23401005
http://dx.doi.org/10.1083/jcb.201208045
Descripción
Sumario:Signal recognition particle (SRP) and its receptor (SR) comprise a highly conserved cellular machine that cotranslationally targets proteins to a protein-conducting channel, the bacterial SecYEG or eukaryotic Sec61p complex, at the target membrane. Whether SecYEG is a passive recipient of the translating ribosome or actively regulates this targeting machinery remains unclear. Here we show that SecYEG drives conformational changes in the cargo-loaded SRP–SR targeting complex that activate it for GTP hydrolysis and for handover of the translating ribosome. These results provide the first evidence that SecYEG actively drives the efficient delivery and unloading of translating ribosomes at the target membrane.