Partially purified colicin K (mCol K) has been obtained from cultures of Escherichia coli K235 induced with mitomycin C. Unlike colicin K (Col K) derived from noninduced cultures of E. coli K235, mitomycin-induced colicin K (mCol K) is not associated with the type O-specific antigen of the colicinogenic bacillus. mCol K elicits in rabbits specific antibodies which precipitate and neutralize the...

Conditions permitting survival (colony formation) of E. coli after treatment with colicin K have been found. Survival required K+ and Mg2+ at concentrations high enough to replace the intracellular ions lost from colicintreated cells. Either glucose minimal medium or broth could support survival. Survival was still observed after colicin-promoted efflux of Rb+ and decline in ATP levels had occu...

The colicin V production and immunity genes were isolated from plasmid pColV-K30. A HindIII-to-SalI fragment of 9.4 kilobases was cloned into the compatible vectors pBR322 and pACYC184. Mutants defective in colicin production were generated by Tn5 insertions and by constructing deletions in vitro. Physical analysis of these mutations identified a 4.4-kilobase region of this DNA which contains a...

In a series of published articles, colicin A has been mistakenly labeled as colicin K.

The kinetics of killing of Escherichia coli K-12 by colicin CA42-E2 have been studied, and the data were used to estimate the adsorption constant of this colicin under various environmental conditions. Evidence was obtained suggesting that the adsorption of colicin occurred in two stages; the earlier stage was reversible and did not lead to the death of the cell, the latter stage was irreversib...

To examine the hypothesis that colicin proteins are subject to diversity-enhancing selection, we studied the rates of synonymous, nonsynonymous, and intergenic nucleotide substitution in three pairs of closely related colicin clusters. The results indicate that the immunity gene and the immunity-binding domain of the colicin gene, which interact to provide specific immunity from the lethal acti...

Escherichia coli was isolated from feral house mice (Mus domesticus) during the course of a mouse plague in the state of Victoria, Australia. The isolates were characterized for the production of colicins and their resistance to the co-occurring colicins. Of the 447 isolates examined, 59% were found to be colicinogenic. Phenotypic and PCR-based genotypic methods were used to determine the types...

The bfe locus codes for the cell surface receptor for vitamin B12, the E colicins, and bacteriophage BF23 in the Escherichia coli outer membrane. When the bfe+ allele, which is closely linked to the argH locus, was introduced into an argH bfe recipient by conjugation, arg+ recombinant cells rapidly and simultaneously acquired sensitivity to colicin E3 and phage BF23. In the reciprocal experimen...

Treatment of the cell envelope of a colicin I-sensitive strain of Escherichia coli with the nonionic detergent Triton X-100 solubilizes an envelope component which forms a complex with 1251-colicin Ia and Ib. A similar component could not be shown in a strain known to be lacking active colicin I receptors. On this basis, this component is assumed to be the colicin I receptor. The colicin I rece...

a variety of probiotic bacteria have been tested to control animal and foodborne pathogenic bacteria in livestock. the mechanism of inhibition of pathogenic bacteria for several of those probiotic microorganisms is mediated by the production of bacteriocins. colicins are probably the group of bacteriocins that have been most thoroughly characterized. colicins are antimicrobial proteins produced...