title: Transcriptional silencing by the mycobacteriophage L5 repressor.
abstract: The success of a temperate bacteriophage is dependent upon its ability to completely shut down expression of its lytic genes during lysogenic growth. Mycobacteriophage L5 accomplishes this by an atypical phage repressor, gp71, which binds to multiple asymmetric DNA sites. L5 gp71 regulates transcription initiation at an early lytic promoter, Pleft, but also affects downstream gene expression at 'stoperator' sites in the phage genome. The L5 genome is replete with stoperator sites located within short intergenic spaces in both the early and late lytic operons and oriented specifically with respect to transcription. Binding of gp71 to these sites results in a strong orientation-dependent polar effect on downstream gene expression and global silencing of prophage gene expression.
authors.affiliation: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Brown
authors.forename: G J
authors.initials: GJ
authors.lastname: Sarkis
authors.forename: C
authors.initials: C
authors.lastname: Wadsworth
authors.forename: G F
authors.initials: GF
authors.lastname: Hatfull
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D018983:DNA Footprinting; D004279:DNA, Viral / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015967:Gene Expression Regulation, Viral; D008969:Molecular Sequence Data; D009160:Mycobacteriophages / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000378:metabolism*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D004279:DNA, Viral; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D014764:Viral Proteins; C080483:gp71 protein, Mycobacteriophage L5