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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
34
pubmed:dateCreated
2001-8-20
pubmed:abstractText
The multifunctional ribonuclease RNase E and the 3'-exonuclease polynucleotide phosphorylase (PNPase) are major components of an Escherichia coli ribonucleolytic "machine" that has been termed the RNA degradosome. Previous work has shown that poly(A) additions to the 3' ends of RNA substrates affect RNA degradation by both of these enzymes. To better understand the mechanism(s) by which poly(A) tails can modulate ribonuclease action, we used selective binding in 1 m salt to identify E. coli proteins that interact at high affinity with poly(A) tracts. We report here that CspE, a member of a family of RNA-binding "cold shock" proteins, and S1, an essential component of the 30 S ribosomal subunit, are poly(A)-binding proteins that interact functionally and physically, respectively, with degradosome ribonucleases. We show that purified CspE impedes poly(A)-mediated 3' to 5' exonucleolytic decay by PNPase by interfering with its digestion through the poly(A) tail and also inhibits both internal cleavage and poly(A) tail removal by RNase E. The ribosomal protein S1, which is known to interact with sequences at the 5' ends of mRNA molecules during the initiation of translation, can bind to both RNase E and PNPase, but in contrast to CspE, did not affect the ribonucleolytic actions of these enzymes. Our findings raise the prospect that E. coli proteins that bind to poly(A) tails may link the functions of degradosomes and ribosomes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31651-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Escherichia coli poly(A)-binding proteins that interact with components of degradosomes or impede RNA decay mediated by polynucleotide phosphorylase and RNase E.
pubmed:affiliation
Department of Genetics and the Program in Cancer Biology, Stanford University School of Medicine, Stanford, California 94305-5120, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.