Nucleotide Sequence andExpression ofcheF, an Essential Genefor Chemotaxis inBacillus subtilis

ThecheFgene,whichisinvolved inchemotaxis inBacillus subtilis, hasbeencloned, expressed, and sequenced. This geneiscontained ina0.7-kilobase PstI DNAfragment that was isolated froma ACharon4A B.subtilis chromosomal DNAlibrary. Thisfragment wassubcloned into theexpression vector pSI-1 andshown tocomplement thecheFmutation bothforchemotaxis andformethanol production inresponsetotheaddition ofattractants. Plasmid-encoded DNAexpression inB.subtilis maxicells indicated that amembrane-associated polypeptide of20-kilodaltons was expressed fromthis 0.7-kilobase DNA.Thenucleotide sequenceofthis DNA fragment was determined, andan openreading framecapable ofencoding a putative 175-amino-acid protein (M, 20,002) was identified. Inan effort tounderstand thefunction ofthecheFprotein, thedosage ofthecheF geneproduct was varied byaltering theconcentration ofIPTG(isopropyl-gB-D-thiogalactopyranoside) during growth. Inthepresenceofhighconcentrations ofIPTG,chemotaxis was inhibited andmethanol production