乳糖菌的晶体结构 4-脱氧-L-threo-5-hexosulose-uronate 醇异构酶 KduI 与基质类似物复合
Hisamu Iwase1, Yuta Yamamoto1, Akifumi Yamada2
11 Laboratory of Basic and Applied Molecular Biotechnology, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University.
Journal of applied glycoscience
|January 19, 2024
概括
乳酸酶菌cillus rhamnosus KduI通过代谢糖氨基酸甘油 (GAG) 对于益生菌殖民至关重要. 这项研究揭示了KduI的活性部位结构,确定了关键残留物和其功能必不可少的金属离子.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 益生菌,包括乳酸菌,通过与细胞外基质中的葡萄糖氨基甘 (GAG) 相互作用来殖民宿主细胞.
- 乳酸细菌拥有能够降解GAG的酶,这一过程对它们的殖民和宿主相互作用至关重要.
研究的目的:
- 为了阐明Lacticaseibacillus rhamnosus 4-deoxy-L-threo-5-hexosulose-uronate ketol-isomerase (KduI) 的结构功能关系.
- 确定参与KduI酶活性的活性部位残留物和辅助因子,这对GAG代谢至关重要.
主要方法:
- 采用X射线晶体学来确定无体和体结合的KduI的晶体结构.
- 用于检测特定氨基酸残留在酶活性部位中的作用,研究了位点定向突变发生.
- 进行了酶活性测定,以评估突变和化剂对KduI功能的影响.
主要成果:
- 晶体结构显示KduI是一种六个子单元β螺旋酶,具有联结裂.
- 关键的残留物和裂内的协调金属离子被确定为活性部位的重要组成部分.
- 突变和抑制研究证实了这些残留物和金属离子在KduI的催化活性中的参与.
结论:
- 这项研究提供了基于联结复合体的KduI活性部位结构的第一个详细报告.
- 这些发现增强了我们对乳酸细菌的GAG代谢及其益生菌机制的理解.
- 鉴定到的活性部位为未来对KduI和相关酶的研究提供了基础.
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