Abstract
mRNA degradation in Escherichia coli is mediated by a combination of exo- and endoribonucleases. We present evidence for a multiprotein complex which includes at least two enzymes that play important roles in mRNA degradation: the exoribonuclease polynucleotide phosphorylase (PNPase) and the endoribonuclease RNase E. An activity which impedes the processive activity of PNPase at stem-loop structures also appears to be associated with the complex. This complex is estimated to have a molecular mass of about 500 kDa and includes several additional polypeptides whose functions are unknown. The identification of a complex which includes several activities associated with mRNA degradation has implications for the mechanisms and co-ordinated control of mRNA degradation.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Bacterial Proteins / genetics
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Bacterial Proteins / isolation & purification
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Bacterial Proteins / metabolism*
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Base Sequence
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Cytoplasm / metabolism
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DNA, Bacterial / genetics
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Endoribonucleases / genetics
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Endoribonucleases / isolation & purification
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Endoribonucleases / metabolism
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Escherichia coli / genetics
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Escherichia coli / metabolism*
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Escherichia coli / ultrastructure
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Microscopy, Immunoelectron
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Molecular Sequence Data
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Multienzyme Complexes / genetics
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Multienzyme Complexes / isolation & purification
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Multienzyme Complexes / metabolism
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Polyribonucleotide Nucleotidyltransferase / genetics
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Polyribonucleotide Nucleotidyltransferase / isolation & purification
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Polyribonucleotide Nucleotidyltransferase / metabolism
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RNA Processing, Post-Transcriptional
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RNA, Messenger / metabolism*
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RNA-Binding Proteins / genetics
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RNA-Binding Proteins / isolation & purification
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RNA-Binding Proteins / metabolism
Substances
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Bacterial Proteins
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DNA, Bacterial
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Multienzyme Complexes
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RNA, Messenger
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RNA-Binding Proteins
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Polyribonucleotide Nucleotidyltransferase
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Endoribonucleases
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ribonuclease E