Proteomic analysis of E. coli MG1655 after removal of oriC

The project aim was to describe proteomic changes in E. coli MG1655 strain after removal of oriC. Temperature-sensitive transcriptional repressor cI857 and its target promoter was used to control the expression of a serine recombinase from bacteriophage phiC31 (phiC31 integrase). cI857 is a temperature-sensitive mutant that represses its target promoter at 30°C, but the repression is relieved at 37°C. We generated an E. coli “switcher” strain in which the oriC sequence in the chromosome is flanked by phiC31-integrase-specific attP and attB sites and in this strain the oriC is irreversibly excised when cells are incubated at 37°C.