FC0034
L7/L12 ribosomal protein  -  Ribosome

Biological function
The acidic L7/L12 is a ribosomal protein, which binds and enhances activity of GTPases. Flexibility and conformation is modulated by binding of elongation factors to the ribosome.

Domain organization/sequence features
L7/L12 has two folded units and a disordered hinge region (32-51), which enables movement of CTD relative to NTD, which is required for ribosomal activity.

Structural evidence
This protein is invisible in crystal structure of the 50S ribosome and highly disordered in 70S. Crystal structures revealed different dimerization modes, which are also enabled by hinge flexibility.

Biochemical evidence
Depletion in L7/L12 inhibits protein synthesis and decreases elongation factor activity. Shortening of the L7/L12 interdomain region decreases the translation rate in vitro and proteins without the interdomain regions are not active. Increasing the length of the interdomain region results in lower level of miscoding. It was shown by site-directed mutagenesis and deletion studies that the length of the interdomain region of the L7/L12 protein, but not the amino acid sequence has a crucial effect on ribosomal function.

Mechanism category
flexibility /entropy modulation