# Transfer RNA (tRNA) > [!info] tRNA Structure > - Typically 70-95 nucleotides long > > ![[Pasted image 20231003205206.png|400]] **formyl-Met-rRNA** - has a formyl group covalentyl bound to the amino group of the methionine - starting codon AUG used fMet instead of Met Translation begins when initiation factors help fMet-tRNA assemble with the 16S rRNA within the 30S subunit Hydrolysis of GTP to GDP is the energy souce of translation initiation - The Pu nucleotide at position 37 of the tRNA serves as a chemical barrier as it cannot form any complementary interactions ## Charging of tRNA Amino-acyl tRNA synthetases (aaRS) catalyze the covalent attachment of amino acids to the corresponding tRNA ## Mitochondrial tRNA