Figure 3.

Expression of FtsY mutants, LacY–FtsY hybrids, and TrpE-Δ198 hybrid. (A) E. coli UT5600 cells transformed with the indicated plasmid were grown overnight, diluted, and induced by IPTG at the exponential growth phase. Cell extracts were subjected to immunoblot analysis with anti FtsY antibodies. (B) E. coli N4156::pAra14-FtsY′ transformed with the indicated plasmids were grown overnight, diluted into LB without arabinose, and induced by IPTG at OD₆₀₀ of ≈0.15. Membrane fractions were separated by SDS/PAGE and subjected to immunoblot analysis with anti-FtsY antibodies. (C) E. coli N4156::pAra14-FtsY′ transformed with the indicated plasmids were grown overnight, diluted into LB without arabinose, and 3 hr later induced for 2 hr by 0.2% arabinose (Ara, for expression of FtsY, lane 2) or by 100 μg per ml of indoleacrylic acid (IAA, for expression of hybrid TrpE-Δ198, lane 4) (19).