Biochemical characterisation of membrane bound proteins of the division machinery in bacteria

• Applicant: Professor Dr. Marc Bramkamp
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2004 to 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5437952

Cell division (cytokinesis) is one of the pivotal biological processes in prokaryotic cells. The site of cell division is usually marked by the assembly of a so called Z-ring which is composed out of the Material tubulin homologue FtsZ. Proteins involved in division localise in a defined hierarchical order to the contractile Z-ring, forming a multisubunit complex, named divisome or septosome. Most of the division proteins contain at least one transmembrane span or are integral membrane proteins. Due to sophisticated fluorescence microscopy methods, recent studies of these proteins have given a detailed picture of the localisation and temporal organisation of the division proteins. Genetic approaches have given insights into some of the properties of the different proteins. However a detailed biochemical characterisation of most of the division proteins is still lacking. This broad and profound lack of knowledge is in some part due to the fact that most division proteins are membrane bound and therefore not easily amenable to overexpression, purification and biochemical characterisation. This research proposal is aimed at answering some of these questions. The proteins RodA and FtsW are thought to facilitate the translocation of cell wall precursors (Lipid II). Biochemical techniques including reconstitution will be used to unravel properties of the proposed "flippase". The division proteins FtsL and DivIC may act as SNARE-like proteins in order to stabilise membrane invagination during cell division. Both proteins will be examined using in vitro and in vivo techniques to provide evidence for their biological role. Furthermore, the influence of turgor effects on cell division and morphogenesis will be examined. The influence of osmotic changes on cytoskeleton and division will be monitored using GFP fusion proteins.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Cooperation Partner: Professor Dr. Jeffery Errington