Role of two flagellin genes in Campylobacter motility

Abstract

Campylobacter coli VC167 T2 has two flagellin genes, flaA and flaB, which share 91.9% sequence identity. TheflaA gene is transcribed from a r28 promoter, and theflaB gene from a cS4 promoter. Gene replacement mutagenesis techniques were used to generate flaA flaB and flaA flaB+ mutants. Both gene products are capable of assembling independently into functional filaments. A flagellar filament composed exclusively of the JaA gene product -is indistinguishable in length from that of the wild type and shows a slight reduction in motility. The flagellar filament composed exclusively of theflaB gene product is severely truncated in length and greatly reduced in motility. Thus, while both flagellins are not necessary for motility, both products are required for a fully active flageilar filament. Although the wld-type flageliar filament is a heteropolymer of the flaA and flaB gene products, immunogold electron microscopy suggests that flaB epitopes are poorly surface exposed along the length of the wild-type filament.

Deletion of a previously uncharacterized flagellar-hook-length control gene fliK modulates the σ 54-dependent regulon in Campylobacter jejuni

“…In Campylobacter species, analysis of the promoter regions of the dual flagellin genes has identified a canonical s 28 -dependent promoter associated with the major flagellin gene flaA, and a canonical s 54 -dependent promoter for the minor flagellin gene flaB, in both C. jejuni (Nuijten et al, 1990) and Campylobacter coli (Guerry et al, 1991). We and others have since confirmed the involvement of s 54 in flagellar biogenesis, and its regulation by an NtrC family regulator FlgR (Carrillo et al, 2004;Hendrixson & DiRita, 2003;Jagannathan et al, 2001;Wosten et al, 2004).…”

“…Strikingly, 11 of the 15 high-scoring, intergenic potential promoters were upstream of genes or gene clusters associated with flagellar motility, and seven of these were associated with 18 genes or gene clusters that were eightfold or higher overexpressed in the fliK knockout mutant by microarray analysis (Table 4). Sequences similar to the E. coli s 28 consensus sequence 59-TAAAGTTT-N11-GCCGATAA-39 (Ide et al, 1999;Park et al, 2001) were identified upstream of flgM (59-TTAAG-TTT-N11-GTCGATAT-39), the flaG-fliD-fliS cluster (59-TTCATAAA-N11-GTCGATAT-39), and the flaA gene (59-TAAAATAT-N11-CACGATAT-39), the latter resembling in position and sequence those identified previously for C. coli (Guerry et al, 1991) and C. jejuni (Nuijten et al, 1990). The s 70 210 consensus sequence, TATAATT and 235 consensus sequence, 59-TTTAAGTNTT-39 (Wosten et al, 1998), were identified for eight other flagellar genes: fliA, fliF, fliL, fliN, fliP, fliQ, flhA and flhB.…”

Colonization of chicks by motility mutants of Campylobacter jejuni demonstrates the importance of flagellin A expression

“…coli, possess two flagellin genes, JEaA andJEaB (Nuijten et al, 1990;Guerry et al, 1990). In C. coli strain VC167, both flagellin genes are expressed and their products are incorporated together into flagella, with flagellin A as the major component (Guerry et al, 1990(Guerry et al, , 1991. In contrast, C. jejuni strain 8 11 16 is able to produce two types of flagella, depending on which flagellin gene is expressed.…”

Genome-wide Expression Analyses of Campylobacter jejuni NCTC11168 Reveals Coordinate Regulation of Motility and Virulence by flhA

“…As in the enterobacteriaceae, the major flagellin, flaA, belongs to class III and is controlled with a 28 promoter in both C. jejuni and H. pylori, and in both of these organisms, the minor flagellin, flaB, is controlled by 54 . Additional flagellar biosynthetic and modification genes regulated by these alternate sigma factors in C. jejuni include the 28 -regulated flaG (22,23) and the 54 -regulated flgD, flgE, and Cj1293 (8,(15)(16)(17)24). In some organisms, including H. pylori, flgM homologues provide negative feedback on 28 (25).…”