文章基本信息

标题：Mechanistic insight into the functional transition of the enzyme guanylate kinase induced by a single mutation
本地全文：下载
作者：Yuebin Zhang ; Huiyan Niu ; Yan Li 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep08405
语种：English
出版社：Springer Nature
摘要：Dramatic functional changes of enzyme usually require scores of alterations in amino acid sequence. However, in the case of guanylate kinase (GK), the functional novelty is induced by a single (S→P) mutation, leading to the functional transition of the enzyme from a phosphoryl transfer kinase into a phosphorprotein interaction domain. Here, by using molecular dynamic (MD) and metadynamics simulations, we provide a comprehensive description of the conformational transitions of the enzyme after mutating serine to proline. Our results suggest that the serine plays a crucial role in maintaining the closed conformation of wild-type GK and the GMP recognition. On the contrary, the S→P mutant exhibits a stable open conformation and loses the ability of ligand binding, which explains its functional transition from the GK enzyme to the GK domain. Furthermore, the free energy profiles (FEPs) obtained by metadymanics clearly demonstrate that the open-closed conformational transition in WT GK is positive correlated with the process of GMP binding, indicating the GMP-induced closing motion of GK enzyme, which is not observed in the mutant. In addition, the FEPs show that the S→P mutation can also leads to the mis-recognition of GMP, explaining the vanishing of catalytic activity of the mutant.