Western blot analyses of CheY1, CheY2, and CheY3 in wild-type and cheY mutant B. burgdorferi cells. Approximately 10 μg protein of cell lysates from the wild-type strain and the indicated cheY mutant strains was subjected to Western blotting and probed with antibodies specific to the CheY proteins (αCheY1, αCheY2, and αCheY3). Samples containing 3 μg lysates were used for the loading control (αDnaK, panel a, rightmost). The approximate molecular masses of CheY1 (11 kDa), CheY2 (10 kDa), CheY3 (14 kDa), and DnaK (72 kDa) were determined based on the masses of marker proteins (not shown). In panel a, lysates from wild-type; cheY1, cheY2, or cheY3 single mutant; and complemented cheY3+ B. burgdorferi cells were probed with the indicated CheY antisera. In panel b, lysates from wild-type, cheY1 cheY2 double mutant (cheY1Y2), and cheY1 cheY2 cheY3 triple mutant B. burgdorferi cells (cheY1Y2Y3) were probed with CheY1, CheY2, and CheY3 antisera.