An α helix to ß barrel domain switch transforms the transcription factor RfaH into a translation factor.
Cell
; 150(2): 291-303, 2012 Jul 20.
Article
em En
| MEDLINE
| ID: mdl-22817892
ABSTRACT
NusG homologs regulate transcription and coupled processes in all living organisms. The Escherichia coli (E. coli) two-domain paralogs NusG and RfaH have conformationally identical N-terminal domains (NTDs) but dramatically different carboxy-terminal domains (CTDs), a ß barrel in NusG and an α hairpin in RfaH. Both NTDs interact with elongating RNA polymerase (RNAP) to reduce pausing. In NusG, NTD and CTD are completely independent, and NusG-CTD interacts with termination factor Rho or ribosomal protein S10. In contrast, RfaH-CTD makes extensive contacts with RfaH-NTD to mask an RNAP-binding site therein. Upon RfaH interaction with its DNA target, the operon polarity suppressor (ops) DNA, RfaH-CTD is released, allowing RfaH-NTD to bind to RNAP. Here, we show that the released RfaH-CTD completely refolds from an all-α to an all-ß conformation identical to that of NusG-CTD. As a consequence, RfaH-CTD binding to S10 is enabled and translation of RfaH-controlled operons is strongly potentiated. PAPERFLICK
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Transativadores
/
Fatores de Alongamento de Peptídeos
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Proteínas de Escherichia coli
/
Escherichia coli
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article