Gao Haixiao, Ayub Maximiliano Juri, Levin Mariano J, Frank Joachim
Howard Hughes Medical Institute, Health Research, Inc., at the Wadsworth Center, Empire State Plaza, Albany, NY 12201-0509, USA.
Proc Natl Acad Sci U S A. 2005 Jul 19;102(29):10206-11. doi: 10.1073/pnas.0500926102. Epub 2005 Jul 12.
We present analysis, by cryo-electron microscopy and single-particle reconstruction, of the structure of the 80S ribosome from Trypanosoma cruzi, the kinetoplastid protozoan pathogen that causes Chagas disease. The density map of the T. cruzi 80S ribosome shows the phylogenetically conserved eukaryotic rRNA core structure, together with distinctive structural features in both the small and large subunits. Remarkably, a previously undescribed helical structure appears in the small subunit in the vicinity of the mRNA exit channel. We propose that this rRNA structure likely participates in the recruitment of ribosome onto the 5' end of mRNA, in facilitating and modulating the initiation of translation that is unique to the trypanosomes.
我们通过冷冻电子显微镜和单颗粒重构技术，对克氏锥虫（一种导致恰加斯病的动基体原生动物病原体）的80S核糖体结构进行了分析。克氏锥虫80S核糖体的密度图显示了系统发育上保守的真核生物rRNA核心结构，以及小亚基和大亚基中独特的结构特征。值得注意的是，在mRNA出口通道附近的小亚基中出现了一种以前未描述过的螺旋结构。我们认为，这种rRNA结构可能参与核糖体在mRNA 5'端的募集，促进和调节锥虫特有的翻译起始过程。
