Ribosomal protein L3 peptide (202-222) is a peptide with the sequenceH2N-Met-Ser-His-Arg-Lys-Tyr-Glu-Ala-Pro-Arg-His-Gly-His-Leu-Gly-Phe-Leu-Pro-Arg-Lys-Arg-amide, MW=2573.

Ribosomes are the particles that catalyze mRNA-directed protein synthesis in all organisms. The codons of the mRNA are exposed on the ribosome to allow tRNA binding. This leads to the incorporation of amino acids into the growing polypeptide chain in accordance with the genetic information. Ribosomal protein L3 is one of the proteins from the large ribosomal subunit. In Escherichia coli, L3 is known to bind to the 23S rRNA and may participate in the formation of the peptidyltransferase center of the ribosome [1][2].

This gene encodes a ribosomal protein that is a component of the 60S subunit. The protein belongs to the L3P family of ribosomal proteins and it is located in the cytoplasm. The protein can bind to the HIV-1 TAR mRNA, and it has been suggested that the protein contributes to Tat-mediated transactivation [3].