Cloning of an Outer Membrane Protein Gene from Campylobacter jejuni

Abstract

An antigen in the outer membrane protein (OMP) fraction of Campylobacter jejuni was identified and characterized. Western blot analysis demonstrated antigenic differences in this protein between two congenic C. jejuni strains. Strain A74/C, which colonizes chickens, expressed the antigen at 34 kDa, while strain A74/O, which poorly colonizes chickens, expressed the antigen at 32 and 34 kDa. A genomic library was constructed in lambdagt11 with DNA from A74/O and screened with antibody raised against C. jejuni OMPs. A clone that possessed a 1.3-kb insert and expressed an immunoreactive protein fused to beta-galactosidase was isolated and purified. DNA sequence analysis revealed the insert contained one open reading frame 864 bases long. The deduced amino acid sequence demonstrated 56.3% similarity with Bacillus steorothermophilus glnH, a glutamine-binding protein, and 54.0% similarity with C. jejuni PEB1, a putative colonization adhesin. Southern hybridization, Northern hybridization, and DNA sequence analyses of the congenic colonizing and noncolonizing strains of C. jejuni failed to distinguish the two strains and revealed only one copy of the gene. Post-translational modification may be an alternate explanation for the antigenic differences seen between the two strains.

Genetic diversity of the Campylobacter genes coding immunodominant proteins

“…gene variability we conducted MLST (multilocus sequence typing) small-scale analysis taking advantage of the databases. The homologs of the presented above genes have been recently described: cjaC (hisJ) by Garvis et al [13]; 1 67^86 forward 1 24^41 forward 1 58^76 forward 2 836^814 reverse 2 863^846 reverse 2 495^475 reverse 3 410^395 reverse 3 311^292 reverse 3 253^269 forward 4 405^386 reverse cjaD, named omp18, by Burnens et al [16] and Konkel et al [12]; cjaA, termed ompH1, by Meisnersmann et al [15]. CjaC (HisJ) is required for histidine transport as was demonstrated by complementation experiment [13].…”

Evaluation of procedures for outer membrane isolation from Campylobacter jejuni

“…However, prediction of OMP genes by the genome sequence is just a starting point toward understanding OMPs that are actually present. Only a handful of C. jejuni proteins have actually been experimentally localized to the outer membrane; they include MOMP (De et al , 2000; Labesse et al , 2001; Zhang et al , 2000), Omp50 (Bolla et al , 2000), FlgE (Kinsella et al , 1997; Luneberg et al , 1998), CadF (Konkel et al , 1997; Monteville & Konkel, 2002; Moser et al , 1997), PEB1 (Pei & Blaser, 1993; Pei et al , 1998), JlpA (Jin et al , 2001), CmeC (Fakhr & Logue, 2007) and OmpH 1 (Meinersmann et al , 1997). It has been estimated that approximately 2–3 % of the Gram-negative genome encodes integral OMPs, and a significant proportion of these are expressed ubiquitously (~0.5 % of the genome, which correlates to about 20 proteins that are abundant in Escherichia coli (Molloy et al , 2000; Wimley, 2003).…”

Surface components of Campylobacter and Helicobacter

“…Several other putative outer membrane proteins have been described. A 32–34‐kDa protein OmpH 1 with homology to glutamine‐binding protein GlnH of Bacillus stearothermophilus showed similarity to PEB1 (Meinersmann et al. 1997).…”

“…Several other putative outer membrane proteins have been described. A 32±34-kDa protein OmpH 1 with homology to glutamine-binding protein GlnH of Bacillus stearothermophilus showed similarity to PEB1 (Meinersmann et al 1997). A 59-kDa protein described by Moser et al (1997) and implicated by ligand immunoblot in binding to INT 407 cell membranes and ®bronectin showed N-terminal sequence identity to CadF (see above), although there is a major discrepancy in molecular weights reported for these two proteins.…”