Characterisation of the bacteriophage T4 comC alpha 55.6 and comCJ mutants. A possible role in an antitermination process.
We have performed a new screen for T4 mutants (comC) that overcome the phage growth restriction caused by the Escherichia coli rho/tabC mutants. We show that one such mutant (comCJ) identifies a different gene from that identified by canonical comC mutants. We compare the regulation of T4 prereplicative transcription in a rho/tabC mutant infected by T4 wild-type, by a canonical comC mutant (comC alpha 55.6) and by comCJ. The transcription rates of the two prereplicative genes 39 and 43 is depressed in a T4 wild-type infected tabC host mutant. When comC alpha 55.6 and/or comCJ single and double mutants are the infecting phages, transcription of genes 39 and 43 is resumed to different extents; in particular, in the double mutant infections there appears to be a synergistic effect on transcription. Furthermore, we find that the comC alpha 55.6 phage mutant affects the transcription rate of the gene rIIA in a wild-type host.
Chiurazzi
M
M
International Institute of Genetics and Biophysics, Naples, Italy. chiurazzi@iigbna.iigb.na.cnr.it
Pulitzer
J F
JF
D017122:Bacteriophage T4 / Q000235:genetics* / Q000254:growth & development; D004926:Escherichia coli / Q000235:genetics / Q000821:virology*; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral; D009154:Mutation; D012367:RNA, Viral / Q000235:genetics; D012234:Rho Factor / Q000378:metabolism; D013728:Terminator Regions, Genetic; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics; D014779:Virus Replication
D012367:RNA, Viral; D012234:Rho Factor; D014157:Transcription Factors; D014764:Viral Proteins; C077241:comC-alpha protein, Enterobacteria phage T4