FIG 3.

Rescue of dominant negative mutations in ftsL by overexpression of active FtsW mutants. SD399 (ftsL::kan/pSD256 [repA^ts::ftsL]) containing derivatives of pSD296 (P_ara::ftsL) with different alleles of ftsL was transformed with derivatives of pSEB429 (P₂₀₄::ftsW) carrying WT ftsW or either of two active alleles of ftsW. Transformants were spot tested at 37°C (to deplete WT FtsL) in the presence of arabinose (to induce the ftsL allele present on derivatives of pSD296) and increasing concentrations of IPTG to induce alleles of ftsW (ftsW, ftsW^M269I or ftsW^E289G). The cartoons below depict the interpretation of the results. On the left, FtsWI is not recruited in the absence of FtsL; center, FtsWI is recruited but not activated in the presence of a dominant negative FtsL mutant; right, active FtsW mutants suppress dominant negative FtsL mutants in one of two ways (see the text).