Structure of the 80S ribosome from Trypanosoma cruzi reveals unique rRNA components

HAIXIAO GAO; MAXIMILIANO JURI AYUB; MARIANO J. LEVIN; JOACHIM FRANK

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

National Academy of Sciences

Año: 2005 vol. 102 p. 10206 - 10211

0027-8424

We present the first analysis, by cryo-electron microscopy (cryo-EM) 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 novel 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 which is unique to the trypanosomes.