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通过库林-RING连接酶形成毫秒Lys48结合的多基链的机制
Joanna Liwocha1, Jerry Li2, Nicholas Purser2
1Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, Germany.
Nature structural & molecular biology
|February 7, 2024
概括
库林-RING连接酶 (CRLs) 和E2酶可以创建特定的多-万用链. 低温EM结构揭示了CRL如何将乌比奎定位为链组装,以及NEDD8如何在这个过程中激活CRL.
科学领域:
- 生物化学 生化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- E3 泛素连接酶和 E2 酶合作将聚泛素链连接到蛋白质上.
- 库林-RING连接酶 (CRL) 是关键的E3s,利用Cdc34/UBE2R家族的E2s生成与Lys48结合的多基因链,调节各种真核细胞过程.
- 精确的分子机制控制的特异性和多无处不在的快速动力学仍然不完全理解.
研究的目的:
- 通过CRL阐明Lys48链接的多基因链形成的结构基础.
- 了解CRL RING域和UBE2R2循环在无处不在期间定位基板中的作用.
- 调查NEDD8激活CRL用于聚-泛胺链组装的机制.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定与E2酶和ubiquitin复合的CRL的高分辨率结构.
- 结构分析侧重于CRL活性部位内的相互作用,包括RING域,UBE2R2循环和无处不在分子.
- 通过结构和生化方法研究了NEDD8对CRL-E2复合体构造和活性的影响.
主要成果:
- 冷-EM结构显示,CRL RING域激活了E2结合的乌比奎丁,并定向了UBE2R2循环.
- 这种精确的定位有助于将乌比奎转移到基质连接的乌比奎,从而使链延长.
- 据证明,NEDD8通过释放RING域来激活CRL,而不与UBE2R2酶直接相互作用,提供了独特的激活机制.
结论:
- 这项研究提供了关键的结构洞察力,了解了CRLs通过Lys48链接的多基因链形成的机制.
- 这些发现强调了CRL RING域和UBE2R2循环在控制E2-ubiquitin定位以实现高效链合成方面的关键作用.
- 独特的NEDD8中介激活机制为CRL监管提供了新的视角,并建议对其他E3-E2系统有更广泛的适用性.
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