Guided cobamide biosynthesis for heterologous production of reductive dehalogenases. Issue 2 (13th December 2018)

• Record Type: Journal Article
• Authors: Schubert, Torsten; von Reuß, Stephan H.; Kunze, Cindy; Paetz, Christian; Kruse, Stefan; Brand‐Schön, Peggy; Nelly, Anita Mac; Nüske, Jörg; Diekert, Gabriele
• Is Part Of: Microbial biotechnology. Volume 12:Issue 2(2019:Mar.)
• Page Start: 346
• Page End: 359
• Publication Date: 2018-12-13
• Subjects: Microbial biotechnology -- Periodicals; Biotechnology; Microbiology; 660.62
• DOI: 10.1111/1751-7915.13339
• Languages: English
• ISSNs: 1751-7915

Abstract

Summary: Cobamides (Cbas) are essential cofactors of reductive dehalogenases (RDases) in organohalide‐respiring bacteria (OHRB). Changes in the Cba structure can influence RDase function. Here, we report on the cofactor versatility or selectivity of Desulfitobacterium RDases produced either in the native organism or heterologously. The susceptibility of Desulfitobacterium hafniense strain DCB‐2 to guided Cba biosynthesis ( i.e . incorporation of exogenous Cba lower ligand base precursors) was analysed. Exogenous benzimidazoles, azabenzimidazoles and 4, 5‐dimethylimidazole were incorporated by the organism into Cbas. When the type of Cba changed, no effect on the turnover rate of the 3‐chloro‐4‐hydroxy‐phenylacetate‐converting enzyme RdhA6 and the 3, 5‐dichlorophenol‐dehalogenating enzyme RdhA3 was observed. The impact of the amendment of Cba lower ligand precursors on RDase function was also investigated in Shimwellia blattae, the Cba producer used for the heterologous production of Desulfitobacterium RDases. The recombinant tetrachloroethene RDase (PceAY51 ) appeared to be non‐selective towards different Cbas. However, the functional production of the 1, 2‐dichloroethane‐dihaloeliminating enzyme (DcaA) of Desulfitobacterium dichloroeliminans was completely prevented in cells producing 5, 6‐dimethylbenzimidazolyl‐Cba, but substantially enhanced in cells that incorporated 5‐methoxybenzimidazole into the Cba cofactor. The results of the study indicate the utilization of a range of different Cbas by Desulfitobacterium RDases with selected representatives apparently preferring distinct Cbas. Abstract : Guided cobamide (Cba) biosynthesis was applied to improve the heterologous production of reductive dehalogenase enzymes (RDases). RDases from Desulfitobacterium spec. were analyzed for the function with structurally different Cba cofactors. Generalists as well as a specialized enzyme were identified.