title: Hfq affects the length and the frequency of short oligo(A) tails at the 3' end of Escherichia coli rpsO mRNAs.
abstract: Polyadenylation plays an important role in RNA degradation in bacterial cells. In Escherichia coli, exoribonucleases, mostly RNase II and polynucleotide phosphorylase, antagonize the synthesis of poly(A) tails by poly(A) polymerase I (PAP I). In accordance with earlier observations showing that only a small fraction of bacterial RNA is polyadenylated, we demonstrate here that approximately 10% of rpsO mRNA harbors short oligo(A) tails ranging from one to five A residues in wild-type cells. We also compared the length, frequency and distribution of poly(A) tails at the 3'-end of rpsO transcripts in vivo in the presence and absence of Hfq, a host factor that in vitro stimulates the activity of PAP I, and found that Hfq affects all three parameters. In the hfq(+) strain the average length of oligo(A) tails and frequency of polyadenylated transcripts was higher than in the hfq(-) strain and a smaller proportion of tails was found at the 3' end of transcripts terminated at the Rho- independent terminator. Our data led us to the conclusion that Hfq is involved in the recognition of 3' RNA extremities by PAP I.
authors.affiliation: UPR 9073 du CNRS, Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Le Derout
authors.forename: Marc
authors.initials: M
authors.lastname: Folichon
authors.forename: Federica
authors.initials: F
authors.lastname: Briani
authors.forename: Gianni
authors.initials: G
authors.lastname: Dehò
authors.forename: Philippe
authors.initials: P
authors.lastname: Régnier
authors.forename: Eliane
authors.initials: E
authors.lastname: Hajnsdorf
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D004722:Endoribonucleases / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005095:Exoribonucleases / Q000378:metabolism; D005838:Genotype; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011061:Poly A / Q000235:genetics* / Q000378:metabolism; D011117:Polyribonucleotide Nucleotidyltransferase / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D020413:3' Untranslated Regions; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C036004:ribosomal protein S15; D011061:Poly A; D011117:Polyribonucleotide Nucleotidyltransferase; D004722:Endoribonucleases; D005095:Exoribonucleases; C022535:exoribonuclease II; C022537:ribonuclease E