We demonstrated that a large AsnC nucleosome-like structure, in conjunction with two LexA molecules, prevent cea8 transcription initiation and that AsnC binding activity is directly modulated by L asparagine. We show that L-asparagine is an environmental factor that has a marked impact on cea8 promoter regulation. Our results show that AsnC also modulates the expression of several other DNase and RNase colicin genes but does not substantially affect pore-forming colicin K gene expression. We propose that selection pressure has “chosen” highly conserved regulators to control colicin expression in E. coli strains, enabling similar colicin gene silencing among bacteria upon exchange of colicinogenic plasmids.
COBISS.SI-ID: 3511887
We constructed a bacterial conjugation-based »kill« - »anti-kill« antimicrobial system employing the well known Escherichia coli probiotic strain Nissle 1917 genetically modified to harbor a conjugative plasmid carrying the »kill« gene (colicin ColE7 activity gene) and a chromosomally encoded »anti-kill« gene (ColE7 immunity gene). The constructed strain acts as a donor in conjugal transfer and its efficiency was tested in several types of conjugal assays. Our results clearly demonstrate that conjugation-based antimicrobial systems can be highly efficient.
COBISS.SI-ID: 3622479
The population of Halobacterium walsbyi was in the studied saltern brine composed of numerous clonal lineages that differd in surface structures including the cell wall. This type of variation probably reflects a number of mechanisms that minimize the infection rate of predating viruses.
COBISS.SI-ID: 3556687
Our results indicate that the innate endophytic bacterial community assists plants in reducing heavy metal toxicity.
COBISS.SI-ID: 3530063
Our study shows extranintestinal pathogenic E. coli strains are isolated from feces of healthy humans.
COBISS.SI-ID: 3326031