Help: Do any one know what E. coli S17-1 lambda pir stands for?

Mikhail Alexeyev malexeyev at biost1.thi.tmc.edu
Sat Jun 1 19:43:12 EST 1996


In article <4oo1je$7i2 at charm.magnus.acs.ohio-state.edu>, gong.9 at osu.edu
(Fangcheng Gong) wrote:

> Hello, To Any One May Be Helpful.
> 
> We have an E. coli S17-1 lambda pir strain, but we don't know whether
> pi protein is activated or deactivated in this strain. If any one have
> information (esp. published references) about this strains, please 
> email me or post response to this news group. Furthermore, can this 
> strain be used to mobilise the pOT182 plasmid(a Tn5-B21 derivative)
> into Gram negative bacteria and mutagenise the genomic or plasmid DNA
> of the recipients? 
> 
> Thank you in advance for your helpful information.
> 
> Fangcheng Gong (gong.9 at osu.edu)
> 
> Ohio State University.

Pi  protein in this strain is supposed to be constitutively expressed (if
present). Pir gene is cloned in lambda prophage. Therefore, if prophage is
present, the strain expresses pi. Whether or not prophage is present can
be checked directly lambda immunity or indirectly (and directly for pi) by
transforming with R6K gamma-ori based plasmid. It will not replicate
without pi. Your plasmid will be mobilised into other gram- if it has mob
region from RK2 or RP4. Tn5-B21, if I am not mistaken, constructed in
Simon's lab, so there is pretty good chance that plasmid is mobilizable.
Check the literature.

Regards,
M. Alexeyev



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