Effects of BpaB or EbfC overproduction by B. burgdorferi, using an anhydrotetracycline (AT)-inducible promoter system. Levels of BpaB, EbfC, ErpA, and ErpY in uninduced (−) and induced (+) bacteria were determined by immunoblotting, using specific antibodies, and densitometry. Lower panels illustrate SDS-PAGE of each bacterial lysate, stained with Coomassie brilliant blue, to confirm equal loading in each lane. Positions of molecular mass standards are shown to the left of each stained gel.