Molecular analysis of the Bacillus subtilis recF function.

recF resides between the dnaN and gyrB genes of Bacillus subtilis. The recF15 mutation results in replacement of a glutamate residue in the wild type with a lysine residue in the mutant RecF protein. We investigated the in vivo regulation of recF using a transcriptional fusion to the xylE gene and assaying mRNA production. We found that novobiocin leads to a four-fold induction in recF gene expression, but this is not observed in a gyrB mutant strain. Enhancement of expression of the recF gene in the presence of novobiocin is unrelated to the SOS response. The RecF protein, which has a predicted molecular mass of 42.2 kDa, does not seem to be involved in its own regulation.