title: Escherichia coli RNase II: characterization of the promoters involved in the transcription of rnb.
abstract: The rnb gene encodes ribonuclease II (RNase II), one of the two major Escherichia coli exonucleases involved in mRNA degradation. In this paper, the rnb transcript is characterized regarding its promoter and terminator regions. The combined results from S1 nuclease protection analysis, DNase I footprinting and gene fusions with lacZ have shown that rnb is expressed from two promoters. S1 nuclease protection analysis and DNA footprinting have shown that rnb has two promoters, P1 and P2. Transcriptional and translational lacZ reporter fusions, constructed to the rnb gene, revealed that P2, the rnb proximal promoter, is stronger than P1. However, P2 is not transcribed in vitro, suggesting that an additional factor is required in vivo. The 3' end of the rnb transcript mapped to a stem-loop structure immediately after the translated region.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apt 127, 2780 Oeiras, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Zilhão
authors.affiliation: Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Plumbridge
authors.affiliation: Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
authors.forename: Eliane
authors.initials: E
authors.lastname: Hajnsdorf
authors.affiliation: Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Régnier
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apt 127, 2780 Oeiras, Portugal.
authors.forename: Cecília M
authors.initials: CM
authors.lastname: Arraiano
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018983:DNA Footprinting; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D005095:Exoribonucleases / Q000235:genetics*; D005798:Genes, Bacterial; D017930:Genes, Reporter; D007763:Lac Operon; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D012333:RNA, Messenger; D005095:Exoribonucleases; C022535:exoribonuclease II