小分子诱导的Vibrio cholerae RTX囊蛋白酶域的全激活
Patrick J Lupardus1, Aimee Shen, Matthew Bogyo
1Department of Molecular and Cellular Physiology and Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
概括
霍乱病毒RTX毒素使用伊诺西六酸盐 (InsP6) 激活其蛋白酶域. 结合InsP6会触发一个全开关,释放毒素的效应域.
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:
- 霍乱病毒RTX是一种破坏性毒素.
- 毒素的活性依赖于其囊蛋白酶域 (CPD) 的自动处理.
研究的目的:
- 阐明通过InsP6.6激活RTX CPD的结构和机制基础.
- 了解InsP6结合如何触发毒素自处理.
主要方法:
- 在2.1安格斯特罗姆分辨率下测定RTX CPD-InsP6复合结构的X射线晶体学.
- 在CPD的位点定向突变发生.
- 生物化学和动力学测试.
主要成果:
- 确定了与InsP6复合的RTX CPD的2.1安格斯特罗姆结构.
- InsP6 结合到一个远离活性部位的保存基本裂.
- 突变和动力学数据显示,InsP6结合会诱导一个全开关.
结论:
- 结合远端裂的InsP6可以全osterically激活RTX CPD.
- 这种激活机制导致自动处理和释放效应器域.
- 这些发现提供了对宿主细胞代谢产物对细菌毒素调节的见解.
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