Final Activity Report Summary - CELLDIV (Analysis of interactions between cell division proteins)
One phase of the project was focussed on a complex composed of three essential proteins that played a central role in cell division of the gram-negative bacteria Escherichia coli. Using a combination of biochemical, genetic and cytological approaches, we made significant progress in the understanding of this complex and we proposed a model of the interactions between these three essential components and the other proteins involved in the cell division machinery.
In a second phase, I exploited the cell division machinery of escherichia coli to develop a novel genetic assay for studying protein-protein interactions under in vivo conditions. In this approach, called 'E. coli artificial septal targeting', an interaction between two proteins was revealed by an easy detectable phenotype, a fluorescence signal in the middle of the cell. Using this assay, I studied the assembly of cell division proteins from the gram-positive bacteria, bacillus subtilis. This investigation helped to characterise interactions between some essential components involved in cell division and to understand the main difference between gram-positive and gram-negative bacteria cell division mechanisms. This study also demonstrated that this new genetic assay might be an efficient tool for detecting stable protein-protein interactions.