Construction of novel molecular mechanism on polysaccharide-forming enzyme and its application

本研究的目的是阐明多糖产生酶和中等大小低聚糖产生酶的结构元素。此外，通过控制结构元件来形成新的寡糖也是本研究的目的。研究结果如下：(1)多糖产生酶：催化氨基酸为两个谷氨酸。多糖形成结构元件位于酶的C-末端。(2)中等大小低聚糖产生酶：确定了其空间结构，其催化残基为天冬氨酸和谷氨酸。对远离催化中心的两个芳香族残基的突变分析表明，其中一个残基提高了酶的功能。

Purpose of this research is the elucidation of structural elements of polysaccharide-producing enzyme and middle-size-oligosaccharide-producing enzyme. Furthermore, the formation of new oligosaccharide is also purpose of this study by controlling the structural element. The obtained results were as follows; (1) Polysaccharide-producing enzyme: Catalytic amino acids were two Glu. Polysaccharide-forming structural element was in the C-terminal region of enzyme. (2) Middle-size-oligosaccharide-producing enzyme: Three-dimensional structure was elucidated, and catalytic residues were Asp and Glu. Mutation analyses of two aromatic residues at sites distant from catalytic center revealed that one residue improved the enzyme function.