Penicillin-binding protein-related factor a is required for proper chromosome segregation in Bacillus subtilis

Previous work has shown that the ponA gene, encoding penicillin-binding protein 1 (PBP1), is in a two-gene operon with pfrA (PBP-related factor A) (also called recU), which encodes a putative 206-residute basic protein (pI = 10.1) with no significant sequence homology to proteins with known functions, Inactivation of prfA results in cells that grow slower and vary significantly in length relative to wild-type cells. We now show that prfA mutant cells have a defect in chromosome segregation resulting in the production of similar to 0.9 to 3% anucleate cells in prfA cultures grown at 30 or 37 degrees C in rich medium and that the lack of PrfA exacerbates the chromosome segregation defect in sme and spoOJ mutant cells. In addition, overexpression of prfA was found to be toxic for and cause nucleoid condensation in Escherichia coli.