Structural Dynamics and Domain Reorientation of a Phosphohexomutase: Long Range Effects and Catalysis

磷酸六异构酶的结构动力学和结构域重新定位：长程效应和催化研究人员将解决有关酶功能的基本问题，酶是存在于所有生物中的复杂的分子机器。特别是，这项工作将定义用于在酶的三维结构中传递信息的路径。该计划将培训年轻的科学家，学习强大的、最先进的生物物理方法及其应用，以揭开生物大分子的奥秘。该项目的研究和相关培训活动将使美国的化学和生物技术行业以及蛋白质科学和生物物理学的研究社区受益。PI将在当地一所小学扩大她的Science ArtReach项目，利用艺术来提高不同学生群体的科学素养。该中心将启动Soutreat，向青少年介绍活细胞分子，并将加强研究生课程中生物物理方法的教学，为劳动大军提供高技能的员工。在结构域间和内部网络中的催化相关运动将在磷酸甘露糖变位酶/磷酸葡萄糖变位酶(PMM/PGM)中进行研究。PMM/PGM是一个大的酶超家族的成员，其成员在碳水化合物的生物合成中起着重要的作用。以往的研究表明，磷酸化和配体结合都会影响该酶的结构和柔韧性。由于磷酸化和变构是人们广泛感兴趣的话题，因此，催化的长程磷酸调节机制对于理解许多酶系统具有重要意义。具体地说，将结合尖端X射线结晶学、核磁共振和蛋白质化学，在结构域取向波动以及通讯和移动残基网络的水平上进行研究。多种酶状态(磷酸化、去磷酸化等)将根据它们的侧链和结构域构象的性质和种群、它们的动力学以及残基网络的传递和动力学来表征。这些特性如何受到共价磷酸化和非共价配体结合的影响将被比较和对比。这将提供一个全面的案例研究，研究酶中的远程通讯，以及通过磷酸化和配体结合进行调节。

Structural dynamics and domain reorientation of a phosphohexomutase: long range effects and catalysis The investigators will address fundamental questions about the functions of enzymes, the intricate molecular machines found in all living things. In particular, this work will define pathways used for transmitting information across the three-dimensional structures of enzymes. The program will train young scientists in powerful, state-of-the-art biophysical methods and their applications for unraveling the mysteries of biological macromolecules. The research and associated training activities in this project will benefit the chemical and biotechnology industries in the U.S., as well as the research communities in protein science and biophysics. The PI will expand her Science ARTreach program at a local elementary school, using art to improve science literacy of a diverse student population. The co-PI will launch Scoutreach to introduce molecules of living cells to adolescent youth and will enhance teaching of biophysical methods in the graduate student curricula, to provide highly skilled employees for the work force. Catalytically relevant motions among domains and in internal networks will be investigated in the enzyme phosphomannomutase/phosphoglucomutase (PMM/PGM). PMM/PGM is a member of a large enzyme superfamily whose members have important roles in carbohydrate biosynthesis. Previous studies showed that both phosphorylation and ligand binding affect the structure and flexibility of this enzyme. As phosphorylation and allostery are topics of wide interest, the mechanisms involved in long-range phospho-regulation of catalysis have implications for understanding many enzyme systems. Specifically, this will be investigated at the levels of fluctuating domain orientations and networks of communicating and mobile residues, using a combination of cutting-edge X-ray crystallography, NMR, and protein chemistry. Multiple enzyme states (phosphorylated, dephosphorylated, etc.) will be characterized in terms of the nature and populations of their side chain and domain conformers, their dynamics, and residue networks of transmission and dynamics. How these characteristics are affected by covalent phosphorylation vs. noncovalent ligand binding will be compared and contrasted. This will provide a comprehensive case study of long-range communication in an enzyme, and its tuning by phosphorylation and ligand binding.