Cryo-EM structures of the 80S ribosomes from human parasites Trichomonas vaginalis and Toxoplasma gondii
Cryo-EM structures of the 80S ribosomes from human parasites Trichomonas vaginalis and Toxoplasma gondii
复制标题
人类寄生虫阴道毛滴虫和弓形虫 80S 核糖体的冷冻电镜结构
DOI：
10.1038/cr.2017.104
复制
发表时间：
2017-10-01
期刊：
影响因子：
44.1
通讯作者：
Gao, Ning
中科院分区：
文献类型：
--
作者：
Li, Zhifei;Guo, Qiang;Gao, Ning
核糖体作为一种普遍存在于所有生物体内的不可或缺的分子机器，通过进化被选为许多抗生素和小分子抑制剂的天然靶标。病原体核糖体的高分辨率结构对于理解致病微生物翻译控制的一般和独特方面至关重要。本文用冷冻电子显微镜技术，对阴道毛滴虫和弓形虫两种人体寄生虫的胞质核糖体结构进行了研究。虽然这两种病原体的核糖体蛋白都是真核生物家族的典型成员，在某些物种特异性插入/延伸和邻近的核糖体RNA(RRNA)扩展片段之间存在协同进化模式，但它们的rRNA大小截然不同。非常有趣的是，阴道毛滴虫的rRNA在大小上与原核生物的rRNA相当，几乎所有真核生物特有的rRNA扩展片段都缺失了。这些结构有助于剖析核糖体蛋白和RNA的进化路径，并可能有助于设计新型翻译抑制剂。
As an indispensable molecular machine universal in all living organisms, the ribosome has been selected by evolution to be the natural target of many antibiotics and small-molecule inhibitors. High-resolution structures of pathogen ribosomes are crucial for understanding the general and unique aspects of translation control in disease-causing microbes. With cryo-electron microscopy technique, we have determined structures of the cytosolic ribosomes from two human parasites, Trichomonas vaginalis and Toxoplasma gondii, at resolution of 3.2–3.4 Å. Although the ribosomal proteins from both pathogens are typical members of eukaryotic families, with a co-evolution pattern between certain species-specific insertions/extensions and neighboring ribosomal RNA (rRNA) expansion segments, the sizes of their rRNAs are sharply different. Very interestingly, rRNAs of T. vaginalis are in size comparable to prokaryotic counterparts, with nearly all the eukaryote-specific rRNA expansion segments missing. These structures facilitate the dissection of evolution path for ribosomal proteins and RNAs, and may aid in design of novel translation inhibitors.