Sean R Connell / Chie Takemoto / Daniel N Wilson / Hongfei Wang / Kazutaka Murayama / Takaho Terada / Mikako Shirouzu / Maximilian Rost / Martin Schüler / Jan Giesebrecht / Marylena Dabrowski / Thorsten Mielke / Paola Fucini / Shigeyuki Yokoyama / Christian M T Spahn /
PubMed 要旨
Elongation factor G (EF-G) catalyzes tRNA translocation on the ribosome. Here a cryo-EM reconstruction of the 70S*EF-G ribosomal complex at 7.3 A resolution and the crystal structure of EF-G-2*GTP, ...Elongation factor G (EF-G) catalyzes tRNA translocation on the ribosome. Here a cryo-EM reconstruction of the 70S*EF-G ribosomal complex at 7.3 A resolution and the crystal structure of EF-G-2*GTP, an EF-G homolog, at 2.2 A resolution are presented. EF-G-2*GTP is structurally distinct from previous EF-G structures, and in the context of the cryo-EM structure, the conformational changes are associated with ribosome binding and activation of the GTP binding pocket. The P loop and switch II approach A2660-A2662 in helix 95 of the 23S rRNA, indicating an important role for these conserved bases. Furthermore, the ordering of the functionally important switch I and II regions, which interact with the bound GTP, is dependent on interactions with the ribosome in the ratcheted conformation. Therefore, a network of interaction with the ribosome establishes the active GTP conformation of EF-G and thus facilitates GTP hydrolysis and tRNA translocation.
EMDB-1315: Structural basis for interaction of the ribosome with the switch regions of GTP-bound elongation factors. PDB-2om7: Structural Basis for Interaction of the Ribosome with the Switch Regions of GTP-bound Elongation Factors 手法: EM (単粒子) / 解像度: 7.3 Å