The Sm-like RNA chaperone Hfq mediates transcription antitermination at Rho-dependent terminators.
EMBO J
; 30(14): 2805-16, 2011 Jun 14.
Article
in En
| MEDLINE
| ID: mdl-21673658
ABSTRACT
In Escherichia coli, the essential motor protein Rho promotes transcription termination in a tightly controlled manner that is not fully understood. Here, we show that the general post-transcriptional regulatory protein Hfq associates with Rho to regulate Rho function. The HfqRho complex can be further stabilized by RNA bridging both factors in a configuration that inhibits the ATP hydrolysis and duplex unwinding activities of Rho and that mediates transcription antitermination at Rho-dependent terminators in vitro and in vivo. Antitermination at a prototypical terminator (λtR1) requires Hfq binding to an A/U-rich transcript region directly upstream from the terminator. Antitermination is modulated by trans-acting factors (NusG or nucleic acid competitors) that affect Hfq association with Rho or RNA. These data unveil a new Hfq function and a novel transcription regulatory mechanism with potentially important implications for bacterial RNA metabolism, gene silencing, and pathogenicity.
Full text:
1
Database:
MEDLINE
Main subject:
Transcription, Genetic
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RNA, Bacterial
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Gene Expression Regulation, Bacterial
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Terminator Regions, Genetic
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Molecular Chaperones
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Escherichia coli Proteins
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Host Factor 1 Protein
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Escherichia coli
Language:
En
Journal:
EMBO J
Year:
2011
Type:
Article
Affiliation country:
France