Premium
The Sm‐like RNA chaperone Hfq mediates transcription antitermination at Rho‐dependent terminators
Author(s) -
Rabhi Makhlouf,
Espéli Olivier,
Schwartz Annie,
Cayrol Bastien,
Rahmouni A Rachid,
Arluison Véronique,
Boudvillain Marc
Publication year - 2011
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2011.192
Subject(s) - antitermination , transcription (linguistics) , chaperone (clinical) , rna , microbiology and biotechnology , chemistry , biology , genetics , rna polymerase , gene , medicine , linguistics , philosophy , pathology
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 Hfq:Rho 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.