Although an mRNA nucleotide sequence dictates the polypeptide sequence to be made, mRNAs do not directly recognize amino acids. Amino acids are instead linked to transfer RNA (tRNA) "adaptor" molecules, which serve as reading heads to decipher the codons of mRNA through base-pairing complementarity (Fig. 2). FIGURE 2 Transfer RNA folding. The tRNA cloverleaf secondary […]
Decoding of the protein message occurs at the ribo-some, after prior attachment of amino acids to the tRNA molecules. Aminoacyl-tRNA synthetases (AARSs) are the family of enzymes responsible for covalent attachment of each amino acid to its correct, or cognate, tRNA molecule. This first step in protein synthesis is responsible for establishing the rules of […]