Catalytic Mechanism and Allosteric Regulation of UDP-Glucose Pyrophosphorylase from Leishmania major
Catalytic Mechanism and Allosteric Regulation of UDP-Glucose Pyrophosphorylase from Leishmania major
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DOI：
10.1021/cs4007777
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发表时间：
2013-12-01
期刊：
影响因子：
12.9
通讯作者：
Fedorov, Roman
中科院分区：
文献类型：
--
作者：
Fuehring, Jana;Cramer, Johannes T.;Fedorov, Roman
UDP-葡萄糖焦磷酸化酶（UGP）是一种重要的核苷酸转移酶，在所有生物体中具有重要意义，并被认为是人类病原体利什曼原虫和锥虫的有吸引力的药物靶标。在这里，我们使用野生型和突变型利什曼原虫主要UGP解决后反应，UTP和UDP-Glc结合状态的晶体结构，并进行动力学和理论化学分析的酶促反应。新数据填补了UGP机制知识中的关键空白，并允许在三个层面上重建完整的酶循环：全局（分子功能块的运动）、局部（单独残基的行为）和化学（酶反应的量子力学描述）。结果被整合到一个模型的UGP活性描述结构变化沿着周期，底物结合，UGP催化，和产品释放的机制。我们的研究揭示了核苷酸转移酶的变构调节机制，特别是在活性位点的化学反应的机械控制。
UDP-glucose pyrophosphorylase (UGP) is a nucleotidyltransferase of central importance in all organisms and considered an attractive drug target in the human pathogens Leishmania and Trypanosoma. Here, we used wild-type and mutant Leishmania major UGP to solve the crystal structures of postreactive, UTP, and UDP-Glc bound states and performed kinetic and theoretical chemistry analysis of the enzymatic reaction. The new data filled critical gaps in the knowledge of the UGP mechanism and allowed reconstructing the complete enzymatic cycle on three levels: global (movements of molecular functional blocks), local (behavior of separate residues), and chemical (quantum mechanical description of enzymatic reaction). Results were integrated into a model of UGP activity describing structural changes along the cycle, the mechanisms of substrate binding, UGP catalysis, and product release. Our study revealed the mechanisms of allosteric regulation common for nucleotidyltransferases and, in particular, the mechanical control of the chemical reaction in the active site.