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Synchronous tRNA movements during translocation on the ribosome are orchestrated by elongation factor G and GTP hydrolysis
Author(s) -
Holtkamp Wolf,
Wintermeyer Wolfgang,
Rodnina Marina V.
Publication year - 2014
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.201400076
Subject(s) - chromosomal translocation , transfer rna , gtp' , ribosome , elongation , microbiology and biotechnology , gtpase , elongation factor , ef tu , translation (biology) , chemistry , biology , biochemistry , rna , enzyme , gene , messenger rna , materials science , ultimate tensile strength , metallurgy
The translocation of tRNAs through the ribosome proceeds through numerous small steps in which tRNAs gradually shift their positions on the small and large ribosomal subunits. The most urgent questions are: (i) whether these intermediates are important; (ii) how the ribosomal translocase, the GTPase elongation factor G (EF‐G), promotes directed movement; and (iii) how the energy of GTP hydrolysis is coupled to movement. In the light of recent advances in biophysical and structural studies, we argue that intermediate states of translocation are snapshots of dynamic fluctuations that guide the movement. In contrast to current models of stepwise translocation, kinetic evidence shows that the tRNAs move synchronously on the two ribosomal subunits in a rapid reaction orchestrated by EF‐G and GTP hydrolysis. EF‐G combines the energy regimes of a GTPase and a motor protein and facilitates tRNA movement by a combination of directed Brownian ratchet and power stroke mechanisms.