结构和核酸结合特征调节的cystathionineβ-合成酶域含有无一个催化域的pyrophosphatase
Ilya M Zamakhov1,2, Viktor A Anashkin1, Andrey V Moiseenko3
1Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119899 Moscow, Russia.
International journal of molecular sciences
|December 23, 2023
概括
调控性囊氨酸β-合成酶 (CBS) 域控制蛋白质功能. 从细菌无机酸盐酶 (CBS-PPase) 中删除一个灵活的CBS域稳定了它的结构,并揭示了它在酶活性和四聚化中的调节作用.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶学 是一种酶学.
背景情况:
- 调节性氨酸β-合成酶 (CBS) 域在蛋白质中很常见,但它们的精确调节机制仍然不太清楚.
- 获取含有CBS域的蛋白质的结构数据是具有挑战性的,因为它们具有固有的灵活性和形成复杂寡合结构的倾向.
研究的目的:
- 调查细菌无机酸盐酶 (CBS-PPase) 中特定的CBS域的结构和功能作用.
- 描述一个缺少最灵活域的截断CBS-PPase变体.
主要方法:
- 蛋白质工程:从细菌无机酸酶中删除一个灵活的CBS域.
- 生物物理特征:使用单粒子电子显微镜和热展开试验进行结构分析.
- 生物化学测定:评估酶活性和结合核酸对核酸的亲缘关系.
主要成果:
- 截断的CBS-PPase,虽然不活跃,但保持了其同位四重体结构和结合体结合能力.
- 删除CBS域增强了蛋白质的稳定性,防止热变性,这表明删除的域在全尺寸酶中起到了破坏稳定的作用.
- 结构分析证实了截断的酶中不寻常的"线性"域互换结构,由AlphaFold2.2.预测.
结论:
- 在CBS-PPase中,CBS域扮演着双重的角色:促进酶四重化和通过核酸结合调节催化活性.
- 删除的CBS域似乎破坏了全尺寸酶结构的稳定性,同时对其调节功能至关重要.
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