Insights into the Biosynthesis of Dehydroalanines in Goadsporin
Insights into the Biosynthesis of Dehydroalanines in Goadsporin
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DOI：
10.1002/cbic.201500541
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发表时间：
2016-02-02
期刊：
影响因子：
3.2
通讯作者：
Onaka, Hiroyasu
中科院分区：
文献类型：
--
作者：
Ozaki, Taro;Kurokawa, Yukari;Onaka, Hiroyasu
高孢菌素中的脱氢丙氨酸被认为是由 GodF 和 GodG 形成的，它们分别与 LanB（一种 I 类羊毛硫肽脱水酶）的 N 端谷氨酰化结构域和 C 端消除结构域略有同源。尽管类似的分离型 LanB 在硫肽中是保守的，并且对于它们的生物合成和生物活性是必不可少的，但这些酶尚未被表征。在这里，我们从 godF 和 godG 破坏子中鉴定出 goadsporinB，其具有未修饰的 Ser4 和 Ser14。 godG 破坏体还产生 goadsporinC，goadsporinB 的谷氨酰化 Ser4 变体。这些结果表明脱氢丙氨酸是通过谷氨酰化和谷氨酸消除形成的。 NMR 分析首次揭示了在 LanB 型酶的催化下，谷氨酰基通过酯键连接到丝氨酸上。我们的研究结果为了解分离型 LanB 在高孢菌素和硫肽生物合成中的功能提供了见解。
Dehydroalanines in goadsporin are proposed to be formed by GodF and GodG, which show slight homology to the N-terminal glutamylation and C-terminal elimination domains, respectively, of LanB, a classI lanthipeptide dehydratase. Although similar, separated-type LanBs are conserved among thiopeptides and indispensable for their biosynthesis and biological activities, these enzymes had not yet been characterized. Here, we identified goadsporinB, which has unmodified Ser4 and Ser14, from both godF and godG disruptants. The godG disruptant also produced goadsporinC, a glutamylated-Ser4 variant of goadsporinB. These results suggested that dehydroalanines are formed by glutamylation and glutamate elimination. NMR analysis revealed for the first time that the glutamyl group was attached to a serine via an ester bond, by the catalysis of LanB-type enzymes. Our findings provide insights into the function of separated-type LanBs involved in the biosynthesis of goadsporin and thiopeptides.