FIG 3.

Alleviation of the K^s of the ΔptsN mutant by overproduction of K⁺ uptake proteins Kup and KdpA′. Tenfold serial dilutions of cultures of the parent strain (JD624 [kdp⁺ trkA kup]) and its ΔptsN::Kan derivative, JD660 (ΔptsN), bearing the plasmids pHYD3025 (vector), pHYD1852 (P_trckup), pTrc99A (vector), and pHYD724 (P_trckdpA′), were spotted on the surface of K₁, K₂₀, K₄₀, and K₁₁₅ glucose agar plates containing 0.1 mM IPTG. pHYD3025 is the vector control for pHYD1852. The dashed arrows indicate the direction of increasing order of cell dilution.