| Type: | Family | Name: | Colicin E1 (microcin) immunity protein |
| Description: | The structural and functional relationships among independently cloned segments of the plasmid ColE1 region that regulates and codes for colicin E1(cea), immunity (imm) and the mitomycin C-induced lethality function (lys) have been analysed []. A model for the structure and expression of the colicin E1 operon has been proposed in which the cea and lys genes are expressed from a single inducible promoter that is controlled by the lexArepressor in response to the SOS system of Escherichia coli[]. The imm gene lies between the cea and lys genes and is expressed by transcription in the opposite direction from a promoter located within the lys gene [].This arrangement indicates that the transcriptional units for all three genes overlap. It is proposed that the formation of anti-sense RNA may be an important element in the coordinate regulation of gene expression in this system []. Hydropathy analysis of the imm gene products suggests that they have hydrophobic domains characteristic of membrane-associated proteins [].The microcin E1 immunity protein is able to protect a cell that harbours the plasmid ColE1 encoding colicin E1 against colicin E1; it is thusessential both for autonomous replication and colicin E1 immunity []. | Short Name: | Microcin |
