FIG. 1.

(a) Construction of the ′phoA plasmid (pTAP). pTAP is a pJF118HE derivative that contains a ′phoA fragment lacking the sequence for the phoA signal sequence. The construction of this vector is described in Materials and Methods. (b) Structure of the plasmid encoding PhoA fusion protein. Truncated sequences from the C-terminal region of each K⁺-pump protein were subcloned into the BamHI site of pTAP. This construction creates an in-frame K⁺-pump protein–PhoA fusion protein under the control of the tac promoter. The fusion site of each K⁺-pump protein–PhoA fusion protein is shown in parentheses (fusion site/total amino acids [a.a.]).