Our group has contributed to the quantitative understanding of FtsZ (from E. coli) oligomerization and assembly in dilute and crowded solutions (Fig. 3, Fig.4). The GTP-mediated assembly and disassembly of FtsZ (a bacterial ancestor of the eukaryotic tubulin) are thought to be essential for the formation of the septal ring. Our current efforts are focused in the biophysical characterization and functional reconstitution of reversible macromolecular associations that lead to the formation of the bacterial proto-ring, both in solution and in membrane systems (including proteoliposomes of different size and supported bilayers). These studies are being done under conditions of osmolarity, volume exclusion and energy supply that mimic the physiological intracellular environment. In parallel we characterize in quantitative terms the interactions between FtsZ and inner bacterial membranes. Our overall objective is to understand factors modulating the association of FtsZ with the bacterial membrane and its dissociation from the membrane. These studies will provide both a rationale and a methodology for identification of substances that can inhibit septosome assembly, and possibly act as a novel class of antibiotics.
[Projects done in collaboration with the groups of Drs. Marisela Vélez (Inst. Nicolás Cabrera, UAM, Madrid), Miguel Vicente (CNB-CSIC, Madrid), and Tanneke den Blaauwen (SILS, Faculty of Science, Univ. Amsterdam, NL)].
Fig. 3: Effect of macromolecular crowding on E. coli FtsZ oligomerization and assembly. [González et al. (2003) J. Biol. Chem. 278:37664-37671].
Fig. 4: Biophysical characterization of E. coli FtsZ polymerization in dilute solutions. [González et al. (2005) PNAS-USA 102:1895-1900; see also Mingorance et al. (2005) J. Biol. Chem. 280:20909-20914].