Ribosomal protein L19 is one of the proteins from the large ribosomal subunit. In Escherichia coli, L19 is known to be located at the 30S-50S ribosomal subunit interface and may play a role in the structure and function of the aminoacyl-tRNA binding site. It belongs to a family of ribosomal proteins which, on the basis of sequence similarities, groups:

• Eubacterial L19.
• Red algal chloroplast L19.
• Cyanelle L19.

L19 is a protein of 120 to 130 amino-acid residues. As a signature pattern, we selected a conserved region in the C-terminal section.