Since the mRNA is devoid of a cap, the 5’ end cannot be identified.
The initiation complex randomly binds the mRNA and moves along until it reaches a ribosomal binding site (RBS).
The RBS sequence is located on the mRNA.
The optimum consensus sequence is AGGAGGU, located approximately 10 nucleotides upstream from the AUG translation start site.
AGGAGGU……… AUG
This sequence is a signal for the initiation of translation.