The translocation of proteins from one compartment to another is an essential feature of cellular life. The proper functioning of extracytoplasmic proteins requires their export to, and productive folding in, the correct cellular compartment. Gram-negative bacteria secrete a wide range of proteins whose functions include biogenesis of organelles, such as Pili and flagella; nutrient acquisition; virulence; and efflux of drugs and other toxins. Export of these proteins to the bacterial surface involves transport across the IM (Inner Membrane), Periplasm, and OM (Outer Membrane) of the cell envelope. All proteins in Escherichia coli are initially synthesized in the cytoplasm then follow a pathway that depends upon their ultimate cellular destination. Many proteins destined for the periplasm are synthesized as precursors carrying [...]