Dataset Information

TmRNAs that encode proteolysis-inducing tags are found in all known bacterial genomes: A two-piece tmRNA functions in Caulobacter.

ABSTRACT: A general mechanism in bacteria to rescue stalled ribosomes and to clear the cell of incomplete polypeptides involves an RNA species, tmRNA (SsrA), which functions as both a tRNA and an mRNA. This RNA encodes a peptide tag that is incorporated at the end of the aberrant polypeptide and targets it for proteolysis. We have identified a circularly permuted version of the tmRNA gene in alpha-proteobacteria as well as in a lineage of cyanobacteria. The genes in these two groups seem to have arisen from two independent permutation events. As a result of the altered genetic structure, these tmRNAs are composed of two distinct RNA molecules. The mature two-piece tmRNAs are predicted to have a tRNA-like domain and an mRNA-like domain similar to those of standard one-piece tmRNAs, with a break located in the loop containing the tag reading frame. A related sequence was found in the mitochondrial genome of Reclinomonas americana, but only the tRNA-like portion is retained. Although several sequence and structural motifs that are conserved among one-piece tmRNAs have been lost, the alpha-proteobacterium Caulobacter crescentus produces a functional two-piece tmRNA.

SUBMITTER: Keiler KC

PROVIDER: S-EPMC16621 | biostudies-literature | 2000 Jul

REPOSITORIES: biostudies-literature

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tmRNAs that encode proteolysis-inducing tags are found in all known bacterial genomes: A two-piece tmRNA functions in Caulobacter.

Keiler K C KC Shapiro L L Williams K P KP

Proceedings of the National Academy of Sciences of the United States of America 20000701 14

A general mechanism in bacteria to rescue stalled ribosomes and to clear the cell of incomplete polypeptides involves an RNA species, tmRNA (SsrA), which functions as both a tRNA and an mRNA. This RNA encodes a peptide tag that is incorporated at the end of the aberrant polypeptide and targets it for proteolysis. We have identified a circularly permuted version of the tmRNA gene in alpha-proteobacteria as well as in a lineage of cyanobacteria. The genes in these two groups seem to have arisen fr ...[more]

PMID: 10884408

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Dataset Information

TmRNAs that encode proteolysis-inducing tags are found in all known bacterial genomes: A two-piece tmRNA functions in Caulobacter.

Publications

tmRNAs that encode proteolysis-inducing tags are found in all known bacterial genomes: A two-piece tmRNA functions in Caulobacter.

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