Presumably, translational coupling occurs during expression of many other C. jejuni operons containing tail-to-head oriented genes with short or no intergenic regions. Acknowledgements We thank Jeff Hansen for critical reading of the manuscript. We also thank Ewa Kosykowska for performing some complementation experiments as well as Lukasz Kozlowski and Janusz M. Bujnicki for RNA sequence

analysis. This work was supported by two grants from Polish Ministry of Science and Higher Education (No. 2P04C 01527 and N N303 #S63845 supplier randurls[1|1|,|CHEM1|]# 341835). Electronic supplementary material Additional file 1: Arylsulfatase (AstA) assay in C. jejuni 81-176 cells. Arylsulfatase (AstA) activity of C. jejuni 81-176 cultivated on MH liquid medium under high- and low-iron conditions (chelator) till the culture reached OD600 ~0,6-0,7. Results are from four assays with each sample performed in triplicate. Values are reported as arylsulphatase units. One unit equals the amount

of arylsulfatase required to generate 1 nmol of nitrophenol h-1 per OD600 of 1. (DOC 34 KB) Additional file 2: Experiment details concerning DsbI stability and glycosylation. (DOC 72 KB) Additional file 3: Influence of the dba /Dba on DsbI stability in E. coli cells. Western blot (anti-rDsbI) analysis of C. AMN-107 cost jejuni/E. coli protein extracts separated by 12% SDS-PAGE. Relative positions of molecular weight markers (lane 1) are listed on the left (in also kilodaltons). Lanes 2-7 contain 20 μg of total proteins from: C. jejuni 81-176 wt (2), E. coli/pBluescript II KS (3), E. coli/pUWM453 (dba-dsbI) (4), E. coli/pUWM454 (dba) (5), E. coli/pUWM455 (dsbI) (6) and E. coli/pUWM456 (dba-dsbI) (7) (DOC 120 KB) Additional file 4: DsbI glycosylation. Western blot (anti-rDsbI) analysis of C. jejuni protein extracts separated by 12% SDS-PAGE. A – proteins isolated from C. jejuni 81-176 wt and pglB isogenic mutant. Relative positions of molecular weight markers (lane 1) are listed on the left (in kilodaltons). Lanes 2 and 3 contain 20 μg of total

proteins from: C. jejuni 81-176 wt (2) and C. jejuni 81-176 pglB::cat (3). B – proteins isolated from C. jejuni 480 AL4 (dsbI::cat) overexpressing DsbI or the mutated version of the protein DsbI. Relative positions of molecular weight markers (lane 1) are listed on the left (in kilodaltons). Lanes 2-4 contain 20 μg of total proteins from: C. jejuni 480 AL4/pUWM762 (DsbI N292A) (2), AL4/pUWM765 (DsbI N340A) (3) and AL4/pUWM769 (the shuttle plasmid containing a wild type copy of the C. jejuni dsbI gene) (4) (DOC 114 KB) References 1. Young KT, Davis LM, Dirita VJ: Campylobacter jejuni : molecular biology and pathogenesis. Nat Rev Microbiol 2007,5(9):665–679.PubMedCrossRef 2. Moore JE, Corcoran D, Dooley JS, Fanning S, Lucey B, Matsuda M, McDowell DA, Megraud F, Millar BC, O’Mahony R, et al.: Campylobacter. Vet Res 2005,36(3):351–382.PubMedCrossRef 3.