Crystal structure of elongation factor 4 bound to a clockwise ratcheted ribosome

• DOI: 10.1126/science.1253525
• Publication Date: 2014-08-07T18:46:21Z
• Authors: Matthieu G. Gagnon; Jinzhong Lin; David Bulkley; Thomas A. Steitz
• Keywords: Elongation factor; Thermus thermophilus; EF-Tu; Peptidyl transferase; A-site; 50S; Eukaryotic Ribosome; Initiation factor

Elongation factor 4 (EF4/LepA) is a highly conserved guanosine triphosphatase translation factor. It was shown to promote back-translocation of tRNAs on posttranslocational ribosome complexes and compete with elongation G for interaction pretranslocational ribosomes, inhibiting the phase protein synthesis. Here, we report crystal structure EF4-guanosine diphosphate bound Thermus thermophilus P-site tRNA at 2.9 angstroms resolution. The C-terminal domain EF4 reaches into peptidyl transferase center interacts acceptor stem peptidyl-tRNA in P site. an unusual state ratcheting 30S subunit rotated clockwise relative 50S subunit, resulting remodeled decoding center. consistent functioning either as back-translocase or sequester.