Dataset Information

Oxidoreductase disulfide bond proteins DsbA and DsbB form an active redox pair in Chlamydia trachomatis, a bacterium with disulfide dependent infection and development.

ABSTRACT: Chlamydia trachomatis is an obligate intracellular bacterium with a distinctive biphasic developmental cycle that alternates between two distinct cell types; the extracellular infectious elementary body (EB) and the intracellular replicating reticulate body (RB). Members of the genus Chlamydia are dependent on the formation and degradation of protein disulfide bonds. Moreover, disulfide cross-linking of EB envelope proteins is critical for the infection phase of the developmental cycle. We have identified in C. trachomatis a homologue of the Disulfide Bond forming membrane protein Escherichia coli (E. coli) DsbB (hereafter named CtDsbB) and-using recombinant purified proteins-demonstrated that it is the redox partner of the previously characterised periplasmic oxidase C. trachomatis Disulfide Bond protein A (CtDsbA). CtDsbA protein was detected in C. trachomatis inclusion vacuoles at 20 h post infection, with more detected at 32 and similar levels at 44 h post infection as the developmental cycle proceeds. As a redox pair, CtDsbA and CtDsbB largely resemble their homologous counterparts in E. coli; CtDsbA is directly oxidised by CtDsbB, in a reaction in which both periplasmic cysteine pairs of CtDsbB are required for complete activity. In our hands, this reaction is slow relative to that observed for E. coli equivalents, although this may reflect a non-native expression system and use of a surrogate quinone cofactor. CtDsbA has a second non-catalytic disulfide bond, which has a small stabilising effect on the protein's thermal stability, but which does not appear to influence the interaction of CtDsbA with its partner protein CtDsbB. Expression of CtDsbA during the RB replicative phase and during RB to EB differentiation coincided with the oxidation of the chlamydial outer membrane complex (COMC). Together with our demonstration of an active redox pairing, our findings suggest a potential role for CtDsbA and CtDsbB in the critical disulfide bond formation step in the highly regulated development cycle.

SUBMITTER: Christensen S

PROVIDER: S-EPMC6752827 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Oxidoreductase disulfide bond proteins DsbA and DsbB form an active redox pair in Chlamydia trachomatis, a bacterium with disulfide dependent infection and development.

Christensen Signe S Halili Maria A MA Strange Natalie N Petit Guillaume A GA Huston Wilhelmina M WM Martin Jennifer L JL McMahon Róisín M RM

PloS one 20190919 9

Chlamydia trachomatis is an obligate intracellular bacterium with a distinctive biphasic developmental cycle that alternates between two distinct cell types; the extracellular infectious elementary body (EB) and the intracellular replicating reticulate body (RB). Members of the genus Chlamydia are dependent on the formation and degradation of protein disulfide bonds. Moreover, disulfide cross-linking of EB envelope proteins is critical for the infection phase of the developmental cycle. We have ...[more]

PMID: 31536549

Similar Datasets

Project description:BackgroundBacterial Dsb enzymes are involved in the oxidative folding of many proteins, through the formation of disulfide bonds between their cysteine residues. The Dsb protein network has been well characterized in cells of the model microorganism Escherichia coli. To gain insight into the functioning of the Dsb system in epsilon-Proteobacteria, where it plays an important role in the colonization process, we studied two homologs of the main Escherichia coli Dsb oxidase (EcDsbA) that are present in the cells of the enteric pathogen Campylobacter jejuni, the most frequently reported bacterial cause of human enteritis in the world.Methods and resultsPhylogenetic analysis suggests the horizontal transfer of the epsilon-Proteobacterial DsbAs from a common ancestor to gamma-Proteobacteria, which then gave rise to the DsbL lineage. Phenotype and enzymatic assays suggest that the two C. jejuni DsbAs play different roles in bacterial cells and have divergent substrate spectra. CjDsbA1 is essential for the motility and autoagglutination phenotypes, while CjDsbA2 has no impact on those processes. CjDsbA1 plays a critical role in the oxidative folding that ensures the activity of alkaline phosphatase CjPhoX, whereas CjDsbA2 is crucial for the activity of arylsulfotransferase CjAstA, encoded within the dsbA2-dsbB-astA operon.ConclusionsOur results show that CjDsbA1 is the primary thiol-oxidoreductase affecting life processes associated with bacterial spread and host colonization, as well as ensuring the oxidative folding of particular protein substrates. In contrast, CjDsbA2 activity does not affect the same processes and so far its oxidative folding activity has been demonstrated for one substrate, arylsulfotransferase CjAstA. The results suggest the cooperation between CjDsbA2 and CjDsbB. In the case of the CjDsbA1, this cooperation is not exclusive and there is probably another protein to be identified in C. jejuni cells that acts to re-oxidize CjDsbA1. Altogether the data presented here constitute the considerable insight to the Epsilonproteobacterial Dsb systems, which have been poorly understood so far.

Dataset Information

Oxidoreductase disulfide bond proteins DsbA and DsbB form an active redox pair in Chlamydia trachomatis, a bacterium with disulfide dependent infection and development.

Publications

Oxidoreductase disulfide bond proteins DsbA and DsbB form an active redox pair in Chlamydia trachomatis, a bacterium with disulfide dependent infection and development.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets