Possible function of the cytoplasmic axial filaments in chromosomal segregation and cellular division of Escherichia coli.

Expression of the cafA gene at 71 min on the E. coli chromosome map by use of a high copy number expression vector caused (1) overproduction of the 51 kDa CafA protein, (2) formation of chains of normal cells and shorter anucleate cells, and (3) formation of flexible, tough structures, which we call 'cytoplasmic axial filaments', running throughout the centre of the chained cells. In this article we shall describe the morphology, physiology and possible functions of the cytoplasmic axial filament structure. This structure could be a strong candidate for one of the procaryotic cytoskeletal/cytokinetic elements functioning in cellular extension and division, chromosomal segregation and other important mechanisms involved in the proliferation of procaryotic cells.