FIG 2.

Zn²⁺ induces the expression of CzcR and D51 in CzcR is a key residue to regulate swimming motility. (A) Translational levels of the complemented CzcR or its variants with D81A and D51A point mutations in the ΔczcR mutant grown in the absence or presence of Zn²⁺. (B) Sequence alignment of the receiver domain of CzcR with other TCS response regulators. Conserved amino acid residues were highlighted with black background and two conserved aspartate residues D8 and D51 were indicated. (C) Examination of swimming motility of the PAO1 WT strain, ΔczcR mutant, and the ΔczcR mutant complemented with czcR or its D8A and D51A variants grown on the plates with the supplementation of Zn²⁺. N.D., not detected.