低温电磁波显示了一个化R域包裹着NBD1催化域在ABC输送器中
Rodolpho Souza Amado de Carvalho1, Md Shamiul Islam Rasel1, Nitesh K Khandelwal1
1Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA.
酸化激活了酵母因子1 (Ycf1) 载体的调节域. 它的结构揭示了关键的相互作用,稳定了运输准备状态,对细胞功能至关重要.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 结合ATP的磁带载体是重要的膜蛋白,参与运输各种基质.
- 这些载体的调节通常涉及对本质上无序的区域的酸化,这给结构性阐明带来了挑战.
研究的目的:
- 确定酵母因子1 (Ycf1) 载体的活性调节域 (R-域) 的结构.
- 确定R域内和Ycf1.1的其他区域的关键相互作用.
- 了解这些相互作用在Ycf1功能中对酸化的作用.
主要方法:
- 对Ycf1 R域的酸化状态进行酶丰富.
- 电子显微镜 (cryo-EM) 用于确定3.23 Å的结构.
- 通过用氨酸,甘氨酸和谷氨酸替换R域段进行系统性突变发生.
- 在需要Ycf1活动的细胞条件下的功能测试.
主要成果:
- 激活Ycf1 R域的冷EM结构揭示了四个酸化残留物及其总体位置.
- 确定了关键相互作用,包括核酸结合域 (NBD1和NBD2) 之间的桥梁以及与R插入区域的相互作用.
- 突变分析证实了R域内大多数结构良好的细分的功能重要性.
结论:
- 酸化通过R域稳定了Ycf1的运输能力状态.
- R域可能包围NBD1以稳定这种激活的形状.
- 对R域调节的结构洞察力为理解ABC传输机制提供了基础.
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