Bacterial translation initiation pathway. The multi-step initiation pathway proceeds through the assembly of an intermediate 30S initiation complex (30S IC) comprised of the small, 30S ribosomal subunit, three initiation factors (IF1, 2 and 3), the messenger RNA (mRNA), and initiator fMet-tRNAfMet. Subsequently, the large, 50S ribosomal subunit joins the 30S IC, the IFs dissociate and the resulting 70S IC enters the translation elongation stage. Figure reproduced, with permission, from Wang et al.42.