Role of Amphipathic α-helix and Division-related Proteins in Bacillus Subtilis

In many bacteria, cell division is initiated by a tubulin-like protein FtsZ, which forms a ring structure known as the Z-ring at midcell. FtsA and SepF are important membrane anchor of Z-ring, which exists widely in bacteria species and binds to the membrane by a C-terminal amphipathic α-helix in a membrane potential-dependent manner. It reported that amphipathic α-helix binds to the leading edge of developing septum with an intrinsic preference. These discoveries led to a hypothesis, proteins of amphipathic helix might not only function as membrane anchor of FtsZ, but also participating the regulation of septum synthesis. Several variants were made by genetic techniques, and cell length measurements were performed by fluorescence microscopy and ImageJ. All helix variants were found viable, the amphipathic α-helix does affect the cell division but does not affect the functionality.