Cytoplasmic axial filaments in Escherichia coli cells: possible function in the mechanism of chromosome segregation and cell division.

Overproduction of CafA caused formation of chained cells and minicells. The cafA gene is located downstream from the mre region at 71 min on the Escherichia coli chromosome map and was previously called orfF. A long axial structure running through the chained cells, consisting of bundles of filaments assembled in a long hexagonal pillar several micrometers long and about 0.1 to 0.2 micron in diameter, was visible in both phase-contrast micrographs of the lysozyme-treated cells and electron micrographs of ultrathin sections. The CafA protein displays 34% amino acid similarity with the N terminus of the Ams protein of E. coli, which cross-reacts with antibody to a nonmuscle myosin heavy chain.