Dominant-negative FtsW mutants localize to the Z ring.

Localization of the FtsW mutants was assessed in the FtsW depletion strain SD237 [W3110, leu::Tn10 ftsW::kan/pDSW406 (P_BAD::ftsW)] using plasmid pSD349 (P₂₀₆::ftsW-l60-gfp) and derivatives carrying ftsW mutations. Overnight cultures of SD237 carrying derivatives of plasmid pSD349 were diluted 1:100 in fresh LB medium with antibiotics and arabinose. 2 hrs later arabinose was removed by centrifugation and washing, and the cells were resuspended in fresh LB and diluted 1:20. IPTG was added to the culture to induce the fusion protein and 4 hours post induction (also removal of arabinose) cells were immobilized on a 2% agarose pad for photographing. Scale bar, 3 μm.