Structural biochemistry of a Vibrio cholerae dinucleotide cyclase reveals cyclase activity regulation by folates
Structural biochemistry of a Vibrio cholerae dinucleotide cyclase reveals cyclase activity regulation by folates
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霍乱弧菌二核苷酸环化酶的结构生物化学揭示叶酸对环化酶活性的调节
DOI：
10.1016/j.molcel.2014.08.001
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Xiang Y.
中科院分区：
文献类型：
--
作者：
Zhu D.;Wang L.;Shang G.;Liu X.;Zhu J.;Lu D.;Wang L.;Kan B.;Zhang J. R.;Xiang Y.
环状二核苷酸是一类新发现的第二信使，参与细菌、真核生物和古细菌细胞中多种不同途径的调控。霍乱弧菌（Vibrio choleraedinucleotide cyclase，简称DncV）是一种新发现的霍乱弧菌（Vibrio choleraedinucleotide cyclase，简称VC 0179）的基因产物，它能产生三种不同的环状核苷酸，并优先合成一种杂合环状GMP-AMP。在这里，我们报告的晶体结构和功能的DncV的研究。我们意外地观察到5-甲基四氢叶酸二谷氨酸（5MTHFGLU 2）分子结合在表面口袋对面的核苷酸底物结合沟的DncV。随后的诱变和功能研究表明，DncV的酶活性受叶酸样分子的调节，这表明存在将叶酸样代谢辅因子与环二核苷酸第二信使合成的调节联系起来的信号通路。序列分析表明，参与5MTHFGLU 2结合的残基在DncV直系同源物中是高度保守的，这意味着在各种细菌中存在这种调节机制。
Cyclic dinucleotides are a newly expanded class of second messengers that contribute to the regulation of multiple different pathways in bacterial, eukaryotic, and archaeal cells. The recently identifiedVibrio choleraedinucleotide cyclase (DncV, the gene product ofVC0179) can generate three different cyclic dinucleotides and preferentially synthesize a hybrid cyclic-GMP-AMP. Here, we report the crystal structural and functional studies of DncV. We unexpectedly observed a 5-methyltetrahydrofolate diglutamate (5MTHFGLU2) molecule bound in a surface pocket opposite the nucleotide substrate-binding groove of DncV. Subsequent mutagenesis and functional studies showed that the enzymatic activity of DncV is regulated by folate-like molecules, suggesting the existence of a signaling pathway that links folate-like metabolism cofactors to the regulation of cyclic dinucleotide second messenger synthesis. Sequence analysis showed that the residues involved in 5MTHFGLU2 binding are highly conserved in DncV orthologs, implying the presence of this regulation mechanism in a wide variety of bacteria.