FLGM IS A PRIMARY REGULATOR OF SIGMA(D) ACTIVITY, AND ITS ABSENCE RESTORES MOTILITY TO A SINR MUTANT

We have used mini-Tn10 mutagenesis to identify negative regulators of sigma(D) activity, Nine independent insertions were mapped to five gen es: flgM, flgK, fliD, fliS, and fliT, suggesting that FlgM export is r egulated similarly in Bacillus subtilis and Salmonella typhimurium. We show that a deletion of flgM can restore sigma(D) activity to a sinR null mutant of B, subtilis, although fla/che operon expression is affe cted by neither SinR nor FlgM.