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 similar to10% 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.
|Titolo:||Hfq affects the length and the frequency of short oligo(A) tails at the 3' end of Escherichia coli rpsO mRNAs|
|Parole Chiave:||ribosomal-protein S20; poly(A) polymerase I; SM-like protein; antisense RNA; polynucleotide phosphorylase; PCNB gene; degradation; decay; polyadenylation; sequence|
|Settore Scientifico Disciplinare:||Settore BIO/18 - Genetica|
Settore BIO/19 - Microbiologia Generale
|Data di pubblicazione:||15-lug-2003|
|Digital Object Identifier (DOI):||10.1093/nar/gkg456|
|Appare nelle tipologie:||01 - Articolo su periodico|