Transcription of the genome of the filamentous bacteriophage cf from both plus and minus DNA strands.
The filamentous bacteriophage cf infects the bacterium Xanthomonas campestris pv. citri. Northern blot analysis with probes derived from various restriction fragments of cf replicative form (RF) DNA has revealed the presence of five major phage-specific transcripts in infected cells. Four of these transcripts were shown to be derived from the region of the cf genome extending from gene II to gene VIII and are consistent with the cascade model of transcription proposed for Ff coliphages. These transcripts overlap with each other and terminate upstream of an efficient Rho-independent transcription terminator. Unlike the well-characterized Ff phages, in which only the minus strand of viral DNA serves as a transcription template, both strands of the RF DNA of phage cf appeared to be transcribed. Thus one of the five major cf transcripts was shown to be derived from a region of the viral minus strand that contains an open reading frame encoding a putative polypeptide of 165 amino acids. Primer extension analysis mapped the transcriptional initiation site of this RNA to a cytosine residue at position 870. A partial transcription map of phage cf revealed two independent regions of transcriptional activity. The region with the highest activity coincides with that encoding the polypeptides required in the largest amounts during the cf infection cycle.
Wang
H J
HJ
Institute of Molecular Biology and Institute of Botany Academia Sinica, Nankang, Taipei, 115, Republic of China.
Cheng
C M
CM
Wang
C N
CN
Kuo
T T
TT
D020121:5' Untranslated Regions; D001435:Bacteriophages / Q000235:genetics*; D004279:DNA, Viral; D016679:Genome, Viral; D012367:RNA, Viral; D014158:Transcription, Genetic; D016959:Xanthomonas campestris / Q000821:virology*
D020121:5' Untranslated Regions; D004279:DNA, Viral; D012367:RNA, Viral