罗多普辛的晶体结构
Wataru Shihoya1, Keiichi Inoue2,3,4,5, Manish Singh2
1Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan.
Nature
|September 27, 2019
概括
新发现的微生物 rhodopsins 具有独特的结构和膜方向. 它们的结构揭示了新的视网膜结合口袋和视网膜吸收的侧面窗口.
科学领域:
- 结构生物学
- 微生物生物化学
- 膜蛋白质
背景情况:
- Heliorhodopsins (HeRs) 是一种近期发现的微生物 rhodopsins,在各种生命形式中发现.
- 尽管与其他罗多素具有共同的关键特征,但HER具有低序列相同性和反向的膜方向.
- 有限的结构和机制信息阻碍了对HER功能和演变的理解.
研究的目的:
- 从未培养的古生物中确定Heliorhodopsin的高分辨率结构.
- 阐明HER与其他微生物素之间的结构相似性和差异.
- 调查光激活机制和HER结构的功能影响.
主要方法:
- 用X射线结晶学来确定HER的2.4-Å分辨率结构.
- 结构分析以将HER与已知的Rhodopsin家族进行比较.
- 生物物理分析以探测确定结构的功能方面.
主要成果:
- 总体上,HER的折叠与细菌素相似,但在视网膜结合的口袋残留物上有显著的差异.
- 在视网膜β-离子环上方,HER具有独特的横向窗体,对于环境视网膜捕获至关重要.
- 细胞外半部分的恐水性残留物可能会阻止质子和离子的透.
结论:
- 确定的HER结构为微生物罗多的结构多样性提供了关键的见解.
- 独特的结构特征,包括侧面的窗体,突出了HERS的新功能适应.
- 这项研究促进了对HER功能及其在罗多普辛超级家族中的进化关系的理解.
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