Structural and Biophysical Analysis of the Soluble DHH/DHHA1-Type Phosphodiesterase TM1595 from Thermotoga maritima
Structural and Biophysical Analysis of the Soluble DHH/DHHA1-Type Phosphodiesterase TM1595 from Thermotoga maritima
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DOI：
10.1016/j.str.2017.10.001
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发表时间：
2017-12-05
期刊：
影响因子：
5.7
通讯作者：
Witte, Gregor
中科院分区：
文献类型：
--
作者：
Drexler, David Jan;Mueller, Martina;Witte, Gregor
细菌细胞中信使分子的浓度需要严格控制。这可以通过分别控制合成速度、降解或特定转运体的出口来实现。对重要的第二信使c-di-AMP的调节是通过调节二腺苷环化酶的活性以及通过在细胞中水解c-di-AMP的特定的磷酸二酯酶来实现的。在这里，我们提供了海洋热水菌的DHH型磷酸二酯酶TmPDE(TM1595)的结构和生化数据。我们的分析表明，与环状二核苷酸底物相比，TmPDE优先降解线状二核苷酸，如5‘-PAPA、5’-pGpG和5‘-pApG。这里提供的高分辨率结构数据描述了PDE反应的所有步骤：无配体酶、两个底物结合状态和三个反应后状态。根据小角X射线散射数据和生化分析，我们进一步表明肺炎链球菌的Pde2具有结构特征和底物特异性。
The concentration of messenger molecules in bacterial cells needs to be tightly regulated. This can be achieved by either controlling the synthesis rate, degradation, or export by specific transporters, respectively. The regulation of the essential second messenger c-di-AMP is achieved by modulation of the diadenylate cyclase activity as well as by specific phosphodiesterases that hydrolyze c-di-AMP in the cell. We provide here structural and biochemical data on the DHH-type phosphodiesterase TmPDE (TM1595) from Thermotoga maritima. Our analysis shows that TmPDE is preferentially degrading linear dinucleotides, such as 5'-pApA, 5'-pGpG, and 5'-pApG, compared with cyclic dinucleotide substrates. The high-resolution structural data provided here describe all steps of the PDE reaction: the ligand-free enzyme, two substrate-bound states, and three post-reaction states. We can furthermore show that Pde2 from Streptococcus pneumoniae shares both structural features and substrate specificity based on small-angle X-ray scattering data and biochemical assays.