COLD-SENSITIVE PHENOTYPE OF ESCHERICHIA-COLI-CELLS HARBORING A PLASMID CARRYING THE KIL GENE OF PHAGE-LAMBDA BROUGHT UNDER CONTROL OF CI857GENE PROMOTERS
Y. Sugino et M. Morita, COLD-SENSITIVE PHENOTYPE OF ESCHERICHIA-COLI-CELLS HARBORING A PLASMID CARRYING THE KIL GENE OF PHAGE-LAMBDA BROUGHT UNDER CONTROL OF CI857GENE PROMOTERS, Gene, 141(1), 1994, pp. 25-30
A plasmid (pI-14), containing part of the phage lambda control region
(EcoRI-D fragment of lambda c1857) with a large deletion between genes
rex and kil, confers a cold-sensitive (cs) phenotype on the host bact
eria, whereas the parent plasmid (pMM200) without the deletion made th
e host bacteria (Escherichia coli strain DOO) high-temperature sensiti
ve. This phenomenon could be explained on the basis of the sequence an
alysis of the deletion. Upon this deletion, the lambda kil gene, which
was originally under the control of the p(L) promoter, was brought un
der the control of the lambda cI promoters, resulting in the reversal
of the host cell response to temperature. This example shows that gene
circuits showing diametrically opposite responses to environmental fa
ctors (in this case, temperature) can be constructed from the same ele
ments when the effector gene (here, kil) is connected in different way
s to the sensor gene (here, c1857). This cold-dependent killing activi
ty was also dependent on the crp(+) state of the host.