FlhF, the third signal recognition particle-GTPase of Bacillus subtilis, is dispensable for protein secretion

Bacillus subtilis contains three proteins of the signal recognition particle-GTPase family known as Ffh, FtsY, and FlhF. Here we show that FlhF is dispensable for protein secretion, unlike Ffh and FtsY. Although flhF is located in the fla/che operon, B. subtilis 168 flhF mutant cells assemble flagella and are motile.