Guided cobamide biosynthesis for heterologous production of reductive dehalogenases
Guided cobamide biosynthesis for heterologous production of reductive dehalogenases
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DOI：
10.1111/1751-7915.13339
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发表时间：
2019-03-01
影响因子：
5.7
通讯作者：
Diekert, Gabriele
中科院分区：
文献类型：
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作者：
Schubert, Torsten;von Reuss, Stephan H.;Diekert, Gabriele
钴酰胺（Cbas）是呼吸有机卤化物细菌（OHRB）还原性脱卤酶（RDases）的重要辅因子。Cba结构的变化可以影响RDase功能。在这里，我们报告的辅因子的多功能性或选择性的脱硫杆菌RDases无论是在本地生物或异源。分析了Desulfitobacterium longniense菌株DCB-2对指导的Cba生物合成（即掺入外源Cba低级配体碱基前体）的敏感性。外源苯并咪唑类、氮杂苯并咪唑类和4，5-二甲基咪唑类被该生物体整合到Cbas中。当Cba的类型改变时，没有观察到对3-氯-4-羟基-苯乙酸转化酶RdhA 6和3，5-二氯苯酚脱卤酶RdhA 3的周转率的影响。还在Shimwellia blattae中研究了Cba低级配体前体的修改对RDase功能的影响，Shimwellia blattae是用于异源生产脱硫杆菌RDase的Cba生产者。重组四氯乙烯RDase（PceA（Y51））对不同的Cbas无选择性。然而，在产生5，6-二甲基苯并咪唑基-Cba的细胞中，完全阻止了消除二氯脱硫杆菌的1，2-二氯乙烷-二卤代消除酶（DcaA）的功能性产生，但在将5-甲氧基苯并咪唑并入Cba辅因子的细胞中，其功能性产生显著增强。该研究的结果表明脱硫杆菌RDases利用一系列不同的Cbas，其中选择的代表明显偏好不同的Cbas。
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 (PceA(Y51)) 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.