The largest of the fragments produced by AluI digestion of phi X174 RFI DNA comprises genes E and J as well as parts of genes D and F. This DNA fragment (1007 bp) was cloned into the lac z' gene of plasmid pUR222. In the recombinant plasmid pUH12, transcription of the phi X174 genes is controlled by
Cell lysis by induction of cloned lambda lysis genes
✍ Scribed by Garrett, Jinnie ;Fusselman, Robert ;Hise, Joseph ;Chiou, Linda ;Smith-Grillo, Dana ;Schulz, John ;Young, Ry
- Publisher
- Springer
- Year
- 1981
- Tongue
- English
- Weight
- 632 KB
- Volume
- 182
- Category
- Article
- ISSN
- 0026-8925
No coin nor oath required. For personal study only.
✦ Synopsis
The lysis gene region of bacteriophage lambda, including genes S, R, and Rz, was cloned into the plasmid pBH20. In the recombinant plasmid, the lysis genes are expressed under the control of the lacOP region. Induction of this "lysis operon" with the lac inducer, IPTG, under conditions where transcription from the lacOP region is not subject to catabolite repression, results in a sharply defined lysis after 35 min. Premature lysis can be accomplished by cyanide, chloramphenicol, or chloroform, exactly as in bacteriophage lambda infected cells. The lysis gene region of an S- mutant was also cloned into pBH20. Induction of the S- lysis operon has no apparent effect on culture growth; however, large quantities of bacteriolytic activity accumulate intracellularly. Neither cyanide nor chloramphenicol causes lysis in the induced S- clones. Thus premature lysis appears to be entirely an S-dependent phenomenon. A model for the control of lysis in bacteriophage lambda infections is presented in which it is the accumulation of the S gene product in competition with a host "anti-S" protein that determines lysis timing.
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