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 pro tein 1 (PBP1), is in a two-gene operon with pfrA (PBP-related factor A) (al so called recU), which encodes a putative 206-residute basic protein (pI = 10.1) with no significant sequence homology to proteins with known function s, Inactivation of prfA results in cells that grow slower and vary signific antly in length relative to wild-type cells. We now show that prfA mutant c ells 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 de grees C in rich medium and that the lack of PrfA exacerbates the chromosome segregation defect in sme and spoOJ mutant cells. In addition, overexpress ion of prfA was found to be toxic for and cause nucleoid condensation in Es cherichia coli.