Structural Features and Domain Movements Controlling Substrate Binding and Cofactor Specificity in Class II HMG-CoA Reductase.
Structural Features and Domain Movements Controlling Substrate Binding and Cofactor Specificity in Class II HMG-CoA Reductase.
复制标题
II 类 HMG-CoA 还原酶中控制底物结合和辅因子特异性的结构特征和结构域运动。
DOI：
10.1021/acs.biochem.7b00999
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发表时间：
2018
期刊：
影响因子：
2.9
通讯作者：
Kung,Yan
中科院分区：
文献类型：
--
作者：
Miller,BradleyR;Kung,Yan
甲羟戊酸途径的关键酶3-羟基-3-甲基戊二酰辅酶A（HMG-CoA）还原酶（HMGR）使用辅因子NAD（P）H将HMG-CoA还原为甲羟戊酸，产生无数代谢产物和天然产物。尽管他汀类药物对HMGR的抑制作用已被充分理解，但HMGR催化的几个机制细节仍未得到解决，并且来自不同生物体的HMGR中对NADH或NADPH的广泛辅因子特异性的结构基础也是未知的。在这里，我们提出的晶体结构的HMGR从肺炎链球菌（SpHMGR）旁边的动力学数据的酶的辅因子的偏好。我们的SpHMGR结合其动力学优选的NADPH辅因子的结构表明如何实现NADPH特异性结合和识别。此外，我们的HMG-CoA结合SpHMGR的结构揭示了大的，以前未知的构象结构域的运动，可以控制HMGR底物结合，并使辅因子交换，而无需中间释放催化循环。总之，这项工作提供了重要的新的见解HMGR反应机制和结构基础的辅因子特异性。
The key mevalonate pathway enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGR) uses the cofactor NAD(P)H to reduce HMG-CoA to mevalonate in the production of countless metabolites and natural products. Although inhibition of HMGR by statin drugs is well-understood, several mechanistic details of HMGR catalysis remain unresolved, and the structural basis for the wide range of cofactor specificity for either NADH or NADPH among HMGRs from different organisms is also unknown. Here, we present crystal structures of HMGR fromStreptococcus pneumoniae(SpHMGR) alongside kinetic data of the enzyme’s cofactor preferences. Our structure of SpHMGR bound with its kinetically preferred NADPH cofactor suggests how NADPH-specific binding and recognition are achieved. In addition, our structure of HMG-CoA-bound SpHMGR reveals large, previously unknown conformational domain movements that may control HMGR substrate binding and enable cofactor exchange without intermediate release during the catalytic cycle. Taken together, this work provides critical new insights into both the HMGR reaction mechanism and the structural basis of cofactor specificity.