Polyadenylation of stable RNA precursors in vivo.
Polyadenylation at the 3' terminus has long been considered a specific feature of mRNA and a few other unstable RNA species. Here we show that stable RNAs in Escherichia coli can be polyadenylated as well. RNA molecules with poly(A) tails are the major products that accumulate for essentially all stable RNA precursors when RNA maturation is slowed because of the absence of processing exoribonucleases; poly(A) tails vary from one to seven residues in length. The polyadenylation process depends on the presence of poly(A) polymerase I. A stochastic competition between the exoribonucleases and poly(A) polymerase is proposed to explain the accumulation of polyadenylated RNAs. These data indicate that polyadenylation is not unique to mRNA, and its widespread occurrence suggests that it serves a more general function in RNA metabolism.
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Department of Biochemistry and Molecular Biology. University of Miami School of Medicine, Miami, FL 33101, USA.
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Deutscher
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D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D029968:Escherichia coli Proteins; D011061:Poly A / Q000378:metabolism*; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D012341:RNA, Ribosomal, 5S / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D029968:Escherichia coli Proteins; D012322:RNA Precursors; D012341:RNA, Ribosomal, 5S; D011061:Poly A; D011062:Polynucleotide Adenylyltransferase; C063643:pcnB protein, E coli