What is the specific mechanism of EF-Tu?
The dissociation of the inorganic phosphate group, which follows the reaction GTPàGDP and Pi causes a shift of a few tenths of a nanometer at the GTP-binding site
b. This tiny movement causes a conformational change to propagate along a crucial piece of alpha helix, called the switch helix, in the Ras-like domain of the protein.
c. The switch helix seems to serve as a latch that adheres to a specific site in another domain of the molecule, holding the protien in a “shut” conformation.d
. The conformational change triggered by GTP hydrolysis causes the switch helix to detach, allowing separate domains of the protein to swing apart, through a distance of about 4 nm.e. This releases the bound tRNA molecule, allowing its attached amino acid to be used.