Adaptation of Escherichia coli at low temperature implicates a drastic reprogramming of gene expression patterns. Mechanisms operating downstream of transcription initiation, such as control of transcription termination, mRNA stability and translatability, play a major role in controlling gene expression in the cold acclimation phase. It was previously shown that Rho-dependent transcription termination within pnp, the gene encoding polynucleotide phosphorylase (PNPase), was suppressed in pnp nonsense mutants, whereas it was restored by complementation with wild type allele. Using a tRNA gene as a reporter and the strong Rho-dependent transcription terminator t (imm) of bacteriophage P4 as a tester, here we show that specific sites in the 5'-untranslated region of pnp mRNA are required for PNPase-sensitive cold-induced suppression of Rho-dependent transcription termination. We suggest that suppression of Rho-dependent transcription termination within pnp and its restoration by PNPase is an autogenous regulatory circuit that modulates pnp expression during cold acclimation.
Titolo: | Autogenous regulation of Escherichia coli polynucleotide phosphorylase during cold acclimation by transcription termination and antitermination |
Autori: | LONGHI, VERA (Secondo) BRIANI, FEDERICA (Penultimo) DEHO', GIOVANNI (Ultimo) |
Parole Chiave: | transcription termination/antitermination; cold shock; polynucleotide phosphorylase |
Settore Scientifico Disciplinare: | Settore BIO/18 - Genetica Settore BIO/19 - Microbiologia Generale |
Data di pubblicazione: | lug-2007 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | 10.1007/s00438-007-0231-3 |
Appare nelle tipologie: | 01 - Articolo su periodico |
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