A molecular chaperone dedicated to folding and translocation of reductive dehalogenases

Reductive dehalogenases (rdhA, RDases) are key enzymes involved in anaerobic organohalide respiration (OHR), during which bacteria are able to use chlorinated compounds as terminal electron acceptors. RDases are redox enzymes containing FeS clusters and a corrinoid as cofactors, and are translocated across the cytoplasmic membrane by the Twin-arginine translocation (Tat) system. In members of Dehalobacter and Desulfitobacterium spp., the product of an accompanying gene, generally named rdhT, was recently proposed to play a role as molecular chaperone in the folding of the reductive dehalogenase (1,2). Recently, this finding was applied to heterologously produce active RDases (3). However, the mechanism by which the molecular chaperone acts on the maturation of RDases is not yet solved. In this study, we investigate the diversity of RdhT chaperones in Dehalobacter restrictus and their interaction with the Tat signal peptide of their cognate redox component, as well as their specificity or cross-reactivity towards alternative signal peptides. To this respect, both in vivo and in vitro experimental approaches are conducted and will be presented. References (1) Morita et al., 2009. Appl. Microbiol. Biotechnol. 83:775. (2) Maillard et al., 2011. Microbiol. 157:2410. (3) Mac Nelly et al., 2014. Appl. Environ. Microbiol. 80:4313.