Abstract
Recently, we found that a multicomponent ribonucleolytic degradosome complex formed around RNase E, a key mRNA-degrading and 9S RNA-processing enzyme, contains RNA in addition to its protein components. Herein we show that the RNA found in the degradosome consists primarily of rRNA fragments that have a range of distinctive sizes. We further show that rRNA degradation is carried out in the degradosome by RNase E cleavage of A+U-rich single-stranded regions of mature 16S and 23S rRNAs. The 5S rRNA, which is known to be generated by RNase E processing of the 9S precursor, was also identified in the degradosome, but tRNAs, which are not cleaved by RNase E in vitro, were absent. Our results, which provide evidence that decay of mature rRNAs occurs in growing Escherichia coli cells in the RNA degradosome, implicate RNase E in degradosome-mediated decay.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Chromatography, Affinity
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Endoribonucleases / immunology
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Endoribonucleases / isolation & purification
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Endoribonucleases / metabolism*
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Escherichia coli / enzymology
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Multienzyme Complexes / immunology
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Multienzyme Complexes / isolation & purification
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Multienzyme Complexes / metabolism*
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Oligopeptides
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Peptides
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Polyribonucleotide Nucleotidyltransferase / immunology
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Polyribonucleotide Nucleotidyltransferase / isolation & purification
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Polyribonucleotide Nucleotidyltransferase / metabolism*
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RNA Helicases*
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RNA Precursors / metabolism
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RNA Processing, Post-Transcriptional*
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RNA, Bacterial / metabolism*
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RNA, Ribosomal / metabolism*
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RNA, Ribosomal, 16S / metabolism
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RNA, Ribosomal, 23S / metabolism
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RNA, Ribosomal, 5S / metabolism
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RNA, Transfer / metabolism
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Substrate Specificity
Substances
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Multienzyme Complexes
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Oligopeptides
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Peptides
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RNA Precursors
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RNA, Bacterial
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RNA, Ribosomal
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RNA, Ribosomal, 16S
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RNA, Ribosomal, 23S
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RNA, Ribosomal, 5S
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degradosome
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RNA, Transfer
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FLAG peptide
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Polyribonucleotide Nucleotidyltransferase
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Endoribonucleases
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ribonuclease E
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RNA Helicases