Division site selection protein DivIVA of Bacillus subtilis has a second distinct function in chromosome segregation during sporulation

DivIVA is a coiled-coil, tropomyosin-like protein of Gram-positive bacteria . Previous work showed that this protein is targeted to division sites and retained at the cell poles after division. In vegetative cells, DivIVA sequ esters the MinCD division inhibitor to the cell poles, thereby helping to d irect cell division to the correct midcell site. We now show that DivIVA ha s a second, quite separate role in sporulating cells of Bacillus subtilis. It again acts at the cell pole but in this case interacts with the chromoso me segregation machinery to help position the oriC region of the chromosome at the cell pole, in preparation for polar division. We isolated mutations in divIVA that separate the protein's role in sporulation from its vegetat ive function in cell division. DivIVA therefore appears to be a bifunctiona l protein with distinct roles in division-site selection and chromosome seg regation.