Ribosomal proteins cross-linked to peptide chain termination release factor 2

Area of Science:

• Molecular Biology
• Ribosome Biochemistry
• Protein-RNA Interactions

Background:

• Ribosomes are essential molecular machines responsible for protein synthesis.
• Peptide chain termination factors, like RF2, play a crucial role in releasing nascent polypeptide chains from the ribosome.
• Understanding the precise interactions between termination factors and ribosomal subunits is key to deciphering translation regulation.

Purpose of the Study:

• To investigate the specific ribosomal proteins that interact with peptide chain termination factor 2 (RF2).
• To map the ribosomal binding domain of RF2 on the Escherichia coli ribosome.
• To elucidate the structural basis of RF2-ribosome complex formation.

Main Methods:

• Covalent cross-linking of RF2 to ribosomal proteins using dimethyl suberimidate.
• Identification of cross-linked ribosomal proteins via immunological and radioimmunological techniques.
• Utilizing antibodies specific for individual ribosomal proteins and RF2.

Main Results:

• Efficient cross-linking of RF2 was observed with ribosomal proteins L2, L7/L12, and L11 of the large (50S) subunit.
• Cross-linking also occurred, to a lesser extent, with small (30S) subunit proteins S6, S17, and S18.
• These findings suggest RF2 binds to a region at the interface of the 30S and 50S ribosomal subunits.

Conclusions:

• The ribosomal binding site for RF2 is localized to a small region at the interface between the 30S and 50S ribosomal subunits.
• RF2 interacts with components of both the small and large ribosomal subunits.
• This study provides insights into the structural organization of the ribosome during translation termination.