Locking
and
Unlocking
Ribosome
Model - According to this model, the ribosome exists in to states, locked and unlocked. In the locked state the 308 and 50S subunits of the ribosome are closely associated, while in the unlocked state ,they drawn somewhat apart. When peptidyl tRNA is in the A site and deacylated tRNA .
In the P site (pre translocation state) the ribosome is considered to be locked. Binding of EF G to the ribosome and hydrolysis of GTP causes the ribosome to become unlocked. The subunits are visualised as being drawn apart by turning on a hinge.
