ISSN:
1617-4623
Keywords:
Colicin E7
;
SOS box
;
Oligonucleotide-directed site specific mutagenesis
;
LexA binding motif
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract In this study, oligonucleotide-directed site-specific mutagenesis was used to change the consensus sequences of the LexA binding motifs in either one of the two SOS-boxes of the ColE7 operon. The results indicated that both mutants produced larger amounts of colicin than cells harboring the wild-type ColE7 plasmid. This finding would imply that two biologically functional SOS boxes exist in the ColE7 operon. In the non-induced state, no lysis of cells harboring wild-type plasmids occurred at 37°C, whereas, cells harboring recombinant plasmids containing either one of the mutated SOS boxes underwent lysis within 100 min under the same conditions. This result indicated that adaptation of two SOS boxes of the ColE operon would obviously tightly control the expression of ColE operons. In such a way that it may prevent excessive expression of the lysis (cel) gene, thus safeguard the host cells from being lysed in ordinary living conditions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02172368
Permalink
