They are both directly responsible for disulfide bond formation. DsbB and DsbI, orthologues of E. coli DsbB, are potentially involved in DsbA1/DsbA2 re-oxidation . C. jejuni genes of the Dsb oxidation pathway are
organized in two clusters located at different chromosomal SB202190 mouse loci: dsbA2-dsbB-astA-dsbA1 and dba-dsbI. AstA (arylsulfatase), encoded by the gene located in the first cluster, transfers arylsulfate groups between aromatic substrates in an adenosine 3′-phosphate-5′phosphosulfate (PAPS)-independent manner, at least in an E. coli strain [19–21], and is a substrate for the Dsb oxidative pathway. Based on specificity toward the donor aromatic substrate, arylsulfatases are classified as PAPS-dependent or PAPS-independent enzymes. The mode of C. jejuni AstA action remains uncharacterized. The dba gene encodes a potential protein of unknown function. Except for dsbA2, C. jejuni dsb genes are highly conserved within the species. Only dsbA2 is variable among strains . An active Dsb system is required for intestinal colonization by Campylobacter, as shown in a chicken infection model. Additionally, C.
jejuni strain 81-176 with a mutated dsbB or dsbI gene showed reduced invasion/intracellular survival ability in T84 cells. These data indicate that some targets of the Dsb system are involved in crucial processes AZD1152 molecular weight of Campylobacter pathogenicity and commensalism . The goal of this work was to analyze C. jejuni dsb oxidative gene expression by characterizing its transcriptional units, and identify control mechanisms and environmental regulatory factors that facilitate
the pathogen’s adaptation to varying living conditions. We show that the dsb genes are arranged in three operons in the genome, and that expression of those operons responds to an environmental stimulus – iron availability. Although transcription of dsbB and dsbI are both altered by iron concentration with Fur protein Chorioepithelioma engagement, they are regulated differently. Thus, by changing Dsb protein abundance, the pathogen can regulate the amounts of many extracytoplasmic virulence factors that are substrates of the Dsb system, depending on the environmental conditions. Additionally, results show that synthesis of DsbI oxidoreductase is strongly controlled by the mechanism of translational coupling. Methods Bacterial strains, plasmids, media and growth conditions Bacterial strains and plasmids used in this study are listed in Table 1. C. jejuni strain 81-176 , and 480  were grown under microaerobic conditions at 37°C in Mueller Hinton (MH) broth, on MH agar or Blood Agar Base No. 2 (BA) containing 5% horse blood. E. coli strains were grown at 37°C in Luria Bertani (LB) broth or on LB agar.