Bacterial 70S ribosome

The ribosome is the universal molecular machine responsible for protein synthesis in all living cells. It reads the genetic code carried by messenger RNA (mRNA) and, with the help of transfer RNA (tRNA), assembles amino acids into a polypeptide chain.

The PDB structure 4V5D shows the complete bacterial 70S ribosome from E. coli, bound to mRNA and tRNA. It is composed of two subunits — the small 30S subunit, which decodes the genetic message, and the large 50S subunit, which catalyzes peptide bond formation.

This structure demonstrates how ribosomes act as a highly coordinated “protein factory,” linking information stored in DNA to the production of functional proteins.

The model represents the complete bacterial ribosome structure. rRNA molecules are shown in yellow and orange, while ribosomal proteins are displayed in blue and purple. The three tRNA molecules, located in the ribosome’s three functional sites, are highlighted in black. The mRNA molecule is depicted in white and is partially visible.