基质识别和核酸特异性的结构基础在III-b类LanKC酶SalKC中
Yifan Li1, Kai Shao1, Yicong Li1
1Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore 117547, Singapore.
ACS chemical biology
|August 29, 2025
概括
我们确定了SalKC的冷EM结构, 一个单一的氨基酸差异解释了它更喜欢ATP而不是GTP,与相关的酶不同.
科学领域:
- 生物化学
- 结构生物学
- 微生物学
背景情况:
- 兰氏是一种具有显著抗菌性能的核糖体合成和转化后修饰 (RiPP).
- 生物合成涉及专门的酶,包括新发现的III-b类LanKC三功能合成酶.
研究的目的:
- 为了阐明Streptococcus salivarius中的SalKC的高分辨率冷电子显微镜 (冷EM) 结构.
- 在生物化学上描述SalKC,并了解其在抗菌性酸盐成熟中的作用.
- 调查III-b类LanKC酶的基质和辅因子选择性的结构基础.
主要方法:
- 高分辨率冷电子显微镜 (冷电子显微镜) 用于结构确定.
- 生物化学测试以评估酶活性和辅助因子偏好.
- 局部定向突变,以确定影响酶功能的关键氨基酸残留物.
主要成果:
- SalKC的冷-EM结构显示了与绑定领导的原子细节保持一致的二元结构.
- SalKC显示出对ATP的偏好,与相关PneKC酶的GTP偏好形成对比.
- 通过突变研究确认,单个氨基酸替代 (SalKC中的Lys303) 是核酸特异性的决定因素.
结论:
- 这项研究为了解III-b类LanKC酶的保存机制和特定适应提供了分子框架.
- 结构和生化见解澄清了SalKC的基质和辅因子选择性,这对于抗菌生物合成至关重要.
- 这些发现突显了特定氨基酸残留在LanKC家族中的酶功能和特异性的重要性.
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