title: A cytosine- over guanosine-rich sequence in RNA activates rho-dependent transcription termination.
abstract: We have constructed an expression vector carrying the Escherichia coli his operon control region to study the ability of defined segments of DNA to cause rho factor-mediated transcription termination both in vivo and in vitro. We have previously identified a consensus motif consisting of a region of high cytosine over guanosine content common to several cryptic intracistronic transcription termination elements unmasked by polar mutations. We show that a DNA fragment possessing features similar to the ones previously identified is capable of causing rho-mediated mediated release of transcripts in vivo and in vitro. The efficiency of termination depends on the length and efficiency of termination depends on the length and relative cytosine over guanosine ratio of the element.
authors.affiliation: Dipartimento di Biologia e Patologia Cellulare e Molecolare, Universitá di Napoli, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Rivellini
authors.forename: P
authors.initials: P
authors.lastname: Alifano
authors.forename: C
authors.initials: C
authors.lastname: Piscitelli
authors.forename: V
authors.initials: V
authors.lastname: Blasi
authors.forename: C B
authors.initials: CB
authors.lastname: Bruni
authors.forename: M S
authors.initials: MS
authors.lastname: Carlomagno
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D016384:Consensus Sequence; D003596:Cytosine / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics*; D005822:Genetic Vectors; D006151:Guanosine / Q000032:analysis; D006639:Histidine / Q000235:genetics; D008969:Molecular Sequence Data; D009876:Operon / Q000235:genetics; D012322:RNA Precursors / Q000737:chemistry / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012234:Rho Factor / Q000378:metabolism*; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
chemical_list: D012322:RNA Precursors; D012234:Rho Factor; D006151:Guanosine; D006639:Histidine; D003596:Cytosine