Whole cell lysates were separated on 3–8% Tris-Acetate buffered PAGE, transferred to nitrocellulose, and immunoblotted with rabbit polyclonal anti-NhhA sera. Lane 1 Benchmark Prestained Marker, approximately 180 kDa marker indicated. Lane 2, 25 µg protein of strain 2A (NhhA expression abolished); Lanes 3 and 11, 25 µg protein of strain 7G2 (parental strain expressing wild type levels of NhhA), Lane 4, 25 µg protein of strain P6ΔOpcA. Lane 5, 12.5 µg protein of strain P6ΔOpcA; Lane 6, 6.25 µg protein of strain P6ΔOpcA; Lane 7 3.125 µg protein of strain P6ΔOpcA; Lane 8, 1.56 µg protein of strain P6ΔOpcA; Lane 9, 0.78 µg protein of strain P6ΔOpcA; Lane 10, 0.39 µg protein of strain P6ΔOpcA.