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SecYEG activates GTPases to drive the completion of cotranslational protein targeting.

ABSTRACT: 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.

SUBMITTER: Akopian D

PROVIDER: S-EPMC3575545 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature

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SecYEG activates GTPases to drive the completion of cotranslational protein targeting.

Akopian David D Dalal Kush K Shen Kuang K Duong Franck F Shan Shu-ou SO

The Journal of cell biology 20130211 4

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 ...[more]

PMID: 23401005

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