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A role for REP sequences in regulating translation.

ABSTRACT: Repetitive extragenic palindromic (REP) sequences are highly structured elements found downstream of ?500 genes in Escherichia coli that result in extensive stem-loop structures in their mRNAs. However, their physiological role has remained elusive. Here, we show that REP sequences can downregulate translation, but only if they are within 15 nt of a termination codon; a spacing of 16 nt has no effect, suggesting that the REP element acts to stall ribosome movement. Ribosome stalling leads to cleavage of the mRNA and induction of the trans-translation process. Using nrdAB as a model, we find that its regulation can be partially reversed by overexpression of RNA helicases and can be fully overcome upon UV stress, emphasizing the importance of this regulatory process. Since 50% of REP-associated genes have these elements within the critical 15 nt, these findings identify a regulatory mechanism with the potential to affect translation from a large number of genes.

SUBMITTER: Liang W

PROVIDER: S-EPMC4427526 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature

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A role for REP sequences in regulating translation.

Liang Wenxing W Rudd Kenneth E KE Deutscher Murray P MP

Molecular cell 20150416 3

Repetitive extragenic palindromic (REP) sequences are highly structured elements found downstream of ∼500 genes in Escherichia coli that result in extensive stem-loop structures in their mRNAs. However, their physiological role has remained elusive. Here, we show that REP sequences can downregulate translation, but only if they are within 15 nt of a termination codon; a spacing of 16 nt has no effect, suggesting that the REP element acts to stall ribosome movement. Ribosome stalling leads to cle ...[more]

PMID: 25891074

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