The CII protein of bacteriophage 186 establishes lysogeny by activating a promoter upstream of the lysogenic promoter.
We have shown previously that the cII gene product of the non-lambdoid temperate bacteriophage 186 is required for the establishment of lysogeny. We show here that CII, a potential helix-turn-helix DNA-binding protein, establishes lysogeny by activating a promoter (PE) which spans the apl/cII intergenic region, upstream of the lysogenic promoter, PL. The start site of the PE transcript (+1) has been mapped by primer extension and we have identified the CII binding determinants at PE by DNase I footprinting. CII binds to inverted repeat sequences separated by two turns of the helix, with binding half-sites centred at the 38 and -58 positions of PE. Oligomerisation studies with purified CII protein indicate that a CII tetramer may be the species that binds to this site. We also show that PE is subject to direct negative feedback by the CI repressor.
Neufing
P J
PJ
Department of Biochemistry, University of Adelaide, Australia.
Shearwin
K E
KE
Camerotto
J
J
Egan
J B
JB
D001483:Base Sequence; D001665:Binding Sites; D003090:Coliphages / Q000235:genetics*; D018983:DNA Footprinting; D004279:DNA, Viral / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins; D008242:Lysogeny / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011487:Protein Conformation; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics*; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C039000:cII protein, bacteriophage lambda; C016649:phage repressor proteins