FIG 4.

Deletions of the P/Q domain (ZipAΔP/Q) or half of the ZipA linker (ZipAΔ1/2) fully suppress the thermosensitivity of the zipA1 temperature-sensitive mutant. WM 5337 (MG1655 zipA1) plus pDSW210F variants expressing WT ZipA, ZipA ΔP/Q, ZipAΔ+/−, or ZipAΔ1/2 on LB plus ampicillin were serially diluted and spotted onto plates containing various concentrations of IPTG at 30°C, 34°C, 37°C, or 42°C. Although ZipAΔ+/− could suppress zipA1 at the partially permissive temperatures of 34°C and 37°C, only ZipA, ZipAΔP/Q, and ZipAΔ1/2 were able to permit full viability at 42°C.