In prokaryotes, the signal peptide directs the pre-protein to the cytoplasmic membrane. However, the signal peptide is not responsible for the final destination of the mature protein; secretory ...

(c) STEM-HAADF image of the ultrathin cross section in (b), showing microcrystals ... which comprises a cytoplasmic membrane (CM), a periplasmic space (PS) and an outer membrane (OM).