کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2188586 | 1096178 | 2007 | 10 صفحه PDF | دانلود رایگان |
Compared to the prokaryotic 70 S ribosome, the eukaryotic 80 S ribosome contains additional ribosomal proteins and extra segments of rRNA, referred to as rRNA expansion segments (ES). These eukaryotic-specific rRNA ES are mainly on the periphery of the 80 S ribosome, as revealed by cryo-electron microscopy (cryo-EM) studies, but their precise function is not known. To address the question of whether the rRNA ES are structurally conserved among 80 S ribosomes of different fungi we performed cryo-electron microscopy on 80 S ribosomes from the thermophilic fungus Thermomyces lanuginosus and compared it to the Saccharomyces cerevisiae 80 S ribosome. Our analysis reveals general structural conservation of the rRNA expansion segments but also changes in ES27 and ES7/39, as well as the absence of a tertiary interaction between ES3 and ES6 in T. lanuginosus. The differences provide a hint on the role of rRNA ES in regulating translation. Furthermore, we show that the stalk region and interactions with elongation factor 2 (eEF2) are different in T. lanuginosus, exhibiting a more extensive contact with domain I of eEF2.
Journal: Journal of Molecular Biology - Volume 369, Issue 2, 1 June 2007, Pages 429–438