Abstract | Bacterial cell division coincides with a gradual contraction of a ring of FtsZ filaments (Z-ring) at the mid cell. The mechanism of Z-ring contraction is unknown. Mechanical estimates and in vitro experiments show that the Z-ring can generate forces. Using computational modeling and fluorescence experiments, we investigate the molecular mechanism of Z-ring contraction. We show that the weak lateral attraction between filaments is sufficient to generate contractile forces. The contraction process does not require a motor mechanism. Possible experiments are proposed to test the model. |