Assembly of Bacillus subtilis FtsA: Effects of pH, ionic strength and nucleotides on FtsA assembly

In this work, the assembly of purified Bacillus subtilis FtsA was analyzed by several complimentary techniques. FtsA assembled to form filaments and bundles and the polymers disassembled upon dilution. FtsA assembled more efficiently at pH 6.0 as compared to that at pH 7.0 or 8.0 and high salt inhibited the assembly of FtsA. FtsA was found to hydrolyze ATP in vitro; however, neither ATP nor ADP influenced the assembly kinetics of FtsA. Though FtsA is a homologue of actin, cytochalasin D did not inhibit the assembly of FtsA. Interestingly, a hydrophobic molecule, 4,4′-dianilino-1,1′-binaphthyl-5,5′-disulfonic acid, inhibited the assembly of FtsA.