NSF-BSF: Unraveling the molecular determinants of protein oligomerization

生命的复杂性是基于生物分子将自己组织成更高阶功能结构的能力。这个项目将研究进化过程如何塑造单个蛋白质自组装成复杂结构的能力，然后产生比单个蛋白质本身可能的新的生物分子功能。从这项研究中获得的见解将有助于蛋白质工程尝试创建酶和其他结构蛋白质的从头开始或扩展功能。该项目还将为K-12教师提供支持和资源，以加强STEM在亚特兰大(克莱顿公司)社会经济困难地区的参与。我们预期，教师层面较强的研究能力将激发K-12学生对STEM活动(如科学博览会)的更大兴趣和参与，从而为专上教育做好更好的准备。本项目将专门关注蛋氨酸S-腺苷转移酶(MAT)，这是一种重要的中枢代谢同源四聚体酶，其同系物的四级结构完整性具有高度变异性。这项研究将评估MAT折叠和(拆解)的热力学和动力学，单个MAT亚单位对分子伴侣的折叠依赖性，中间MAT亚复合体的聚集倾向，以及组装的MAT复合体的细胞内周转和活性。现有序列的比较分析将与连接祖先和派生状态的中间步骤的祖先序列重建相辅相成。该项目将产生细菌菌株，其中编码内源性MAT同源异构体的基因被现有的或祖先重建的同源基因所取代，使这些菌株在各种环境条件下接受实验室进化，并在实验室进化的限制下尽可能最好地确定适应的遗传、结构、功能和系统决定因素。通过这种多方面的方法，该项目将为同源进化提供一个基因-表型-适合性联系。该项目由遗传机制和生物科学局分子和细胞生物科学部的分子生物物理学项目共同资助。这一美国/以色列合作项目得到美国国家科学基金会和以色列双国科学基金会的支持。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The complexity of life is predicated on the ability of biomolecules to organize themselves into higher-order functional structures. This project will investigate how evolutionary processes shape the ability of individual proteins to self-assemble into complex structures that then generate new biomolecular functionalities than possible for the individual proteins themselves. Insights gained from this research will be useful for protein engineering attempts to create de novo or expanded functionalities of enzymes and other structural proteins. The project will also provide support and resources for K-12 teachers to enhance STEM participation in a socioeconomically challenged section of Atlanta (Clayton Co.). We anticipate that stronger research literacy at the teacher level will generate greater interest and participation of K-12 students in STEM activities such as science fairs, resulting in better preparation for post-secondary education.This project will specifically focus on methionine S-adenosyltransferases (MATs), an essential homo-tetrameric enzyme of central metabolism characterized by high variability in quaternary structure integrity among its homologs. The research will assess thermodynamics and kinetics of MAT folding and (dis)assembly, folding dependency of individual MAT subunits on molecular chaperones, aggregation propensity of intermediate MAT sub-complexes, and the intracellular turnover and activity of assembled MAT complexes. Comparative analysis of extant sequences will be complemented with ancestral sequence reconstruction of the intermediate steps linking ancestral and derived states. The project will generate bacterial strains in which genes encoding the endogenous MAT homomers are replaced with extant or ancestrally reconstructed orthologs, subject the strains to laboratory evolution in a variety of environmental conditions, and identify the genetic, structural, functional and systems determinants of adaptation as best possible given the constraints of laboratory evolution. Through this multifaceted approach, the project will enable a genotype-phenotype-fitness connection for homomer evolution.This project is jointly funded by the Genetic Mechanisms an.d Molecular Biophysics programs of the Molecular and Cellular Biosciences Division in the Biological Sciences Directorate.This collaborative US/Israel project is supported by the US National Science Foundation and the Israeli Binational Science Foundation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.