YsxC, a putative CTP-binding protein essential for growth of Bacillus subtilis 168

YsxC is a member of a family of GTP-binding proteins carried by a diverse r ange of organisms from bacteria to yeasts, plants, and humans. To resolve t he issue of whether ysxC of Bacillus subtilis is essential for growth, we a ttempted to construct mutants in which ysxC was either inactivated or place d under the control of an inducible promoter. Viable mutants were obtained only in the latter case, and these were inducer dependent, demonstrating un ambiguously that ysxC is an essential gene.