Final answer:
In bacteria, translation initiation is relatively simple and involves the small 30S ribosome, mRNA template, initiation factors, formylated methionine, and a special initiator tRNA.
Step-by-step explanation:
In bacteria, translation initiation is relatively simple compared to eukaryotic cells. In bacteria, the initiation complex involves the small 30S ribosome, the mRNA template, three initiation factors, guanosine triphosphate (GTP), and a special initiator tRNA carrying N-formyl-methionine (fMet-tRNAMet). The initiator tRNA interacts with the start codon AUG of the mRNA and carries a formylated methionine. On the other hand, in eukaryotes, the initiation complex includes a different specialized tRNA carrying methionine, called Met-tRNAi. Instead of binding to the mRNA at the Shine-Dalgarno sequence like in bacteria, eukaryotic initiation complex recognizes the 5' cap of the eukaryotic mRNA and tracks along the mRNA until the AUG start codon is recognized. At this point, the 60S subunit binds to the complex of Met-tRNAi, mRNA, and the 40S subunit.