Functional interactions of the translation elongation factors.

Molecular Biophysics, Lund University
â—‹Anders - Liljas Anders - Liljas

Structural biology has made an enormous change to the field of translation, particularly due to the crystallographic and EM analysis of the ribosome. However, much remains to be clarified.
The translation factors are needed to get the rate and fidelity required for protein synthesis. They catalyse protein synthesis on the ribosome. Several of the translation factors are GTPases and are structurally and functionally related. EF-Tu and EF-G are the GTPases in the elongation phase of translation. They catalyse irreversible steps in the process. EF-Tu catalyses the binding of a cognate tRNA to the ribosomal A-site. After peptidyl transfer EF-G catalyses the translocation of peptidyl-tRNA from the A- to the P-site.
The translational GTPases are normally inactive enzymes, but at a suitable state, the ribosome activates their inherent capacity to hydrolyse GTP. An important interaction occurs with the ribosomal protein complex (L10*L124) whose structure and function is slowly becoming understood. Through a number of different approaches the conformational dynamics of the factors and their interplay with the ribosome becomes clarified.