Translation initiation.

1. The small ribosomal subunit binds to several initiation factors (IF1, 2, 3); this complex binds to mRNA.
   
   
   
   
2. Initiator tRNA^fmet binds to mRNA AUG codon in the P (peptidyl) site GTP is hydrolyzed to provide energy for the reactions.
   
   
   
   
   
3. Large subunit binds to complex. Elongation factor Tu binds to the next tRNA, facilitating entry into the A (aminoacyl) site.