将大肠杆菌的遗传密码扩展为素
Hee-Sung Park1, Michael J Hohn, Takuya Umehara
1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
概括
研究人员使用大肠杆菌菌株设计了一种系统,用于将共翻译O-素 (Sep) 纳入蛋白质中. 这扩展了蛋白质工程和疾病研究的遗传密码.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 合成生物学 合成生物学
背景情况:
- O-素 (Sep) 是真核生物中最丰富的氨酸,但不是基因编码的.
- Sep是以翻译后的方式合成的,限制其在合成过程中直接纳入蛋白质.
研究的目的:
- 开发一种工程系统,用于将O-Phosphoserine在蛋白质中进行特定的协译合并.
- 通过在所需的蛋白质位置上实现定向Sep插入来扩展遗传密码.
主要方法:
- 设计了一种含有Sep接受转移RNA (tRNA(Sep) 的大肠杆菌菌株,其相关的Sep-tRNA合成酶 (SepRS) 和一个工程延长因子Tu (EF-Sep).
- 重新设计EF-Tu以放松其质量控制功能,促进Sep-tRNA (Sep) 结合.
- 合成活化的人类线素激活ERK激活激酶1 (MEK1) 与配译插入的Sep残留物.
主要成果:
- 成功证明了由UAG编码子指导的O-Phosphoserine合译的纳入.
- 在MEK1的正规位置中实现了1或2个Sep残留物的特定插入 (Sep(218),Sep(222).
- 验证了系统扩展非正规氨基酸插入遗传密码的能力.
结论:
- 该工程系统允许精确的,特定于特定地点的O-Phosphoserine的共翻译性纳入.
- 这一进步在蛋白质工程,分子生物学和疾病研究中具有广泛的应用.
- 能够直接合成脂蛋白的能力为研究蛋白质功能和调节提供了新的途径.
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