Discovering new enzymes and metabolic pathways:: Conversion of succinate to propionate by Escherichia coli
Discovering new enzymes and metabolic pathways:: Conversion of succinate to propionate by Escherichia coli
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DOI：
10.1021/bi992888d
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发表时间：
2000-04-25
期刊：
影响因子：
2.9
通讯作者：
Gerlt, JA
中科院分区：
文献类型：
--
作者：
Haller, T;Buckel, T;Gerlt, JA
大肠杆菌基因组编码7个类似的crotonase（烯酰辅酶a水合酶）超家族。其中四种具有未知或不确定的功能；在大肠杆菌基因组测序计划完成之前，它们的存在是未知的。编码其中之一的基因YgfG位于一个四基因操纵子中，该操纵子编码甲基丙二酰辅酶a突变酶（Sbm）和酰基辅酶a转移酶（YgfH）的同源物，以及一种推定的蛋白激酶（YgfD/ArgK）。我们确定YgfG为甲基丙二酰辅酶a脱羧酶，YgfH为丙二酰辅酶a：琥珀酸辅酶a转移酶，Sbm为甲基丙二酰辅酶a变化酶。这些反应足以形成一个代谢循环，大肠杆菌可以催化琥珀酸脱羧为丙酸，尽管这个循环的代谢背景尚不清楚。鉴定YgfG为甲基丙二酰辅酶a脱羧酶，扩大了巴豆酶超家族成员催化的反应范围。
The Escherichia coli genome encodes seven paralogues of the crotonase (enoyl CoA hydratase) superfamily. Four of these have unknown or uncertain functions; their existence was unknown prior to the completion of the E. coli genome sequencing project. The gene encoding one of these, YgfG, is located in a four-gene operon that encodes homologues of methylmalonyl CoA mutases (Sbm) and acyl CoA transferases (YgfH) as well as a putative protein kinase (YgfD/ArgK). We have determined that YgfG is methylmalonyl CoA decarboxylase, YgfH is propionyl CoA:succinate CoA transferase, and Sbm is methylmalonyl CoA mutase. These reactions are sufficient to form a metabolic cycle by which E. coli can catalyze the decarboxylation of succinate to propionate, although the metabolic context of this cycle is unknown. The identification of YgfG as methylmalonyl CoA decarboxylase expands the range of reactions catalyzed by members of the crotonase superfamily.