Inducible expression and cellular location of AgrB, a protein involved in the maturation of the staphylococcal quorum-sensing pheromone

AgrB has been suggested to be responsible for the posttranslational modific ation in staphylococci that leads to the production of the thiolactone-cont aining agr peptide pheromone. We demonstrate that AgrB is located in the cy toplasmic membrane. Vectors were constructed for the xylose-inducible overe xpression of agrB, and of agrB and agrD together. A Staphylococcus epidermi dis strain deleted for agr and containing these vectors was assayed for Agr B protein and pheromone production. The lack of adequate pheromone producti on suggests the involvement of additional factors in the production of the agr pheromone.