Expression of the flgFG operon of Campylobacter jejuni in Escherichia coliyields an extra fusion protein

Two Campylobacter jejuni genes with homology to the Escherichia coli flgF a nd flgG genes encoding two of the basal body rod proteins were isolated, an d the nucleotide sequence was determined and analyzed. These two C. jejuni genes were shown, by Northern hybridization analysis, to function as a sing le operon (flgFG). Two transcriptional start sites were detected upstream o f flgF corresponding to the two RNA transcripts detected in the Northern bl ot. Western blot immunoassays using anti-FlgF and anti-FlgG antibodies demo nstrated the synthesis of FlgF and FlgG proteins in C. jejuni and in Escher ichia coli containing the C. jejuni flgF and flgG genes. Maxicell analysis and Western immunoblots using anti-FlgF antibodies to probe flgFG-encoded p roteins in E. coli revealed the presence of a protein with a molecular mass of approximately the combined mass of the FlgF and FlgG proteins. Anti-Flg F antibodies detected in C. jejuni cell extracts the native FlgF protein an d also a higher-molecular-weight protein that is likely encoded by the flgF and part of the flgG sequences. (C) 1998 Elsevier Science B.V. All rights reserved.