Mutations on FtsZ lateral helix H3 that disrupt cell viability hamper reorganization of polymers on lipid surfaces

FtsZ is a bacterial cytoskeletal protein that forms a contractile ring at the midcell. In vivo studies had previously indicated that two mutants, E83Q and R85Q, with mutations in the lateral H3 helix, were unable to support bacterial division. In this paper we report in vitro studies of these mutants on lipid surfaces that show that they cannot form filament aggregates on E.coli lipids, indicating that lateral interactions between filaments are probably required for their condensation into functional constricting rings in vivo.303