Biosynthesis and function of novel modified heptoses present in bacterial surface polysaccharides

一些细菌的表面覆盖着长链的糖链，这些糖链影响它们与宿主细胞的相互作用，以及它们在环境中或在新宿主殖民期间遇到的不利生长条件下生存的能力。这些糖有时是非常不寻常的。它们的确切功能和影响与宿主细胞相互作用的机制尚不清楚。为了更好地了解它们的功能，有必要确定它们合成所必需的基因，以及由这些基因编码的酶的特征。我们正在关注在几种细菌(耶尔森亚科，弯曲杆菌)表面发现的不寻常的七糖，并以耶尔森亚科为模型系统，在阐明它们的生物合成和功能方面取得了很大进展。我们建议使用弯曲杆菌来继续我们的研究，因为在弯曲杆菌中，不寻常的七糖是另一种不同类型的表面大分子的一部分。在我们的研究中收集的基础知识将帮助我们理解特定的糖如何影响大分子的功能，这是糖生物学领域的核心问题，不仅适用于细菌，也适用于植物和动物。我们还计划对我们已确定的酶进行广泛的结构/功能研究，因为这将为设计具有技术应用的新型糖衍生物提供新的工具。

Some bacteria cover their surface with long chains of sugars that affect their interactions with host cells and their ability to survive to adverse growth conditions encountered in the environment or during the colonization of a new host. These sugars can sometimes be very unusual. Their exact function and the mechanism whereby they affect interactions with host cells are not known. To better understand their function, it is necessary to identify the genes that are necessary for their synthesis, as well as to characterize the enzymes that are encoded by the genes. We are focusing on unusual heptoses that are found on the surface of several bacteria (Yersiniae, Campylobacters) and have made great progress in elucidating their biosynthesis and function using Yersiniae as a model system. We propose to pursue our studies using Campylobacters as the unusual heptoses are part of a different type of surface macromolecule in Campylobacters. The fundamental knowledge gathered in our studies will help us understand how a specific sugar can affect the function of a macromolecule, a question that is at the heart of the field of glycobiology and that applies not only to bacteria but also to plants and animals. We also plan to perform extensive structure/function studies of the enzymes that we have identified as this will provide novel tools to engineer novel sugar derivatives that could have technological applications