title: Transcription termination within the iron transport-biosynthesis operon of Vibrio anguillarum requires an antisense RNA.
abstract: The iron transport-biosynthesis (ITB) operon in Vibrio anguillarum includes four genes for ferric siderophore transport, fatD, -C, -B, and -A, and two genes for siderophore biosynthesis, angR and angT. This cluster plays an important role in the virulence mechanisms of this bacterium. Despite being part of the same polycistronic mRNA, the relative levels of transcription for the fat portion and for the whole ITB message differ profoundly, the levels of the fat transcript being about 17-fold higher. Using S1 nuclease mapping, lacZ transcriptional fusions, and in vitro studies, we were able to show that the differential gene expression within the ITB operon is due to termination of transcription between the fatA and angR genes, although a few transcripts proceeded beyond the termination site to the end of this operon. This termination process requires a 427-nucleotide antisense RNA that spans the intergenic region and acts as a novel transcriptional terminator.
authors.affiliation: Department of Molecular Microbiology and Immunology L-220, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97201-3098, USA.
authors.forename: Michiel
authors.initials: M
authors.lastname: Stork
authors.forename: Manuela
authors.initials: M
authors.lastname: Di Lorenzo
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Welch
authors.forename: Jorge H
authors.initials: JH
authors.lastname: Crosa
mesh_terms: D019677:Artificial Gene Fusion; D001483:Base Sequence; D021901:DNA, Intergenic / Q000235:genetics; D007501:Iron / Q000378:metabolism; D007763:Lac Operon; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009876:Operon / Q000235:genetics*; D016372:RNA, Antisense / Q000502:physiology*; D012329:RNA, Bacterial / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017262:Siderophores / Q000096:biosynthesis; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism; D013728:Terminator Regions, Genetic / Q000235:genetics*; D014158:Transcription, Genetic; D014733:Vibrio / Q000235:genetics* / Q000378:metabolism; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D021901:DNA, Intergenic; D016372:RNA, Antisense; D012329:RNA, Bacterial; D012333:RNA, Messenger; D017262:Siderophores; D007501:Iron; D015719:Single-Strand Specific DNA and RNA Endonucleases; D001616:beta-Galactosidase