GenK-catalyzed C-6' methylation in the biosynthesis of gentamicin: isolation and characterization of a cobalamin-dependent radical SAM enzyme.
GenK-catalyzed C-6' methylation in the biosynthesis of gentamicin: isolation and characterization of a cobalamin-dependent radical SAM enzyme.
复制标题
DOI：
10.1021/ja312641f
复制
发表时间：
2013-06-05
影响因子：
15
通讯作者：
Liu HW
中科院分区：
文献类型：
--
作者：
Kim HJ;McCarty RM;Ogasawara Y;Liu YN;Mansoorabadi SO;LeVieux J;Liu HW
钴胺素（Cbl）依赖性酶的存在，是自由基S-腺苷-L-甲硫氨酸（SAM）超家族的成员先前预测基于生物信息学分析。其中一些是Cbl依赖性甲基转移酶，但其反应机制的细节仍不清楚。在这份报告中，我们证明了在体外活性的基因K，CBL依赖自由基SAM酶甲基化未活化的SP3碳在庆大霉素，氨基糖苷类抗生素的生物合成。研究GenK反应的化学计量的实验显示，对于由GenK催化的每个甲基化反应，产生各一当量的5′-脱氧腺苷和S-腺苷-高半胱氨酸。此外，同位素标记实验表明，S-甲基从SAM转移到Cbl和氨基糖苷类产品在反应过程中。基于这些结果，一个机械的可能性GenK反应可以被排除，并进一步的问题有关的机制，CBL依赖的自由基SAM甲基转移酶，在一般情况下，进行了讨论。
The existence of cobalamin (Cbl)-dependent enzymes that are members of the radical S-adenosyl-L-methionine (SAM) superfamily was previously predicted based on bioinformatic analysis. A number of these are Cbl-dependent methyltransferases but the details surrounding their reaction mechanisms have remained unclear. In this report we demonstrate the in vitro activity of GenK, a Cbl-dependent radical SAM enzyme that methylates an unactivated sp3 carbon during the biosynthesis of gentamicin, an aminoglycoside antibiotic. Experiments to investigate the stoichiometry of the GenK reaction revealed that one equivalent each of 5′-deoxyadenosine and S-adenosyl-homocysteine are produced for each methylation reaction catalyzed by GenK. Furthermore, isotope-labeling experiments demonstrate that the S-methyl group from SAM is transferred to Cbl and the aminoglycoside product during the course of the reaction. Based on these results, one mechanistic possibility for the GenK reaction can be ruled out and further questions regarding the mechanisms of Cbl-dependent radical SAM methyltransferases, in general, are discussed.
登录
查看更多内容
自由基介导的酶促甲基化：两个 SAMS 的故事
影响因子：
18.3
作者：
Zhang, Qi;van der Donk, Wilfred A.;Liu, Wen
通讯作者：
Liu, Wen
影响因子：
7.8
作者：
Booker, Squire J.
通讯作者：
Booker, Squire J.
影响因子：
6.8
作者：
Matthews, Rowena G.;Koutmos, Markos;Datta, Supratim
通讯作者：
Datta, Supratim
DOI：
10.1073/pnas.97.12.6908
发表时间：
2000-06-06
影响因子：
11.1
作者：
Gough, SP;Petersen, BO;Duus, JO
通讯作者：
Duus, JO
影响因子：
4.9
作者：
Woodyer, Ryan D.;Li, Gongyong;van der Donk, Wilfred A.
通讯作者：
van der Donk, Wilfred A.