In 1970, Gnter Blobel conducted experiments on the translocation of proteins across membranes. He was awarded the 1999 Nobel prize for his findings. He discovered that many proteins have a signal sequence, that is, a short amino acid sequence at one end that functions like a postal code for the target organelle. The translation of mRNA into protein by a ribosome takes place within the cytosol. If the synthesized proteins "belong" in a different organelle, they can be transported there in either of two ways depending on the protein: Co-translational translocation (translocation during the process of translation), and post-translational translocation (translocation after the process of translation is complete).
In gram-negative bacteria proteins may be incorporated into the plasma membrane, the outer membrane, the periplasm or secreted into the environment. Systems for secreting proteins across the bacterial outer membrane may be quite complex and play key roles in pathogenesis. These systems may be described as type I secretion, type II secretion, etc.
In 1907, Stevens resigned as chief engineer, having in his view made success certain. His replacement, appointed by President Theodore Roosevelt, was U.S. Army Major George Washington Goethals of the U.S. Army Corps of Engineers (soon to be promoted to lieutenant colonel and later to colonel), a strong, United States Military Academytrained leader and civil engineer with experience of canals (unlike Stevens). Goethals would direct the work in Panama to a successful conclusion.
Goethals divided the engineering and excavation work into three divisions: Atlantic, Central, and Pacific. The Atlantic Division, under Major William L. Sibert, was responsible for construction of the massive breakwater at the entrance to Limon Bay, the Gatun locks and their 5.6 km (3.5 mi) approach channel, and the immense Gatun Dam. The Pacific Division, under Sydney B. Williamson (the only civilian member of this high-level team), was similarly responsible for the Pacific 4.8 km (3.0 mi) breakwater in Panama Bay, the approach channel to the locks, and the Miraflores and Pedro Miguel locks and their associated dams and reservoirs.
The Central Division, under Major David du Bose Gaillard of the United States Army Corps of Engineers, was assigned one of the most difficult parts: excavating the Culebra Cut through the continental divide to connect Gatun Lake to the Pacific Panama Canal locks.
On October 10, 1913, President Woodrow Wilson sent a signal from the White House by telegraph which triggered the explosion that destroyed the Gamboa Dike. This flooded the Culebra Cut, thereby joining the Atlantic and Pacific Oceans. Alexandre La Valley (a floating crane built by Lobnitz & Company, and launched in 1887) was the first self-propelled vessel to transit the canal from ocean to ocean. This vessel crossed the canal from the Atlantic in stages during construction, finally reaching the Pacific on January 7, 1914. SS Cristobal (a cargo and passenger ship built by Maryland Steel, and launched in 1902 as SS Tremont) was the first ship to transit the canal from ocean to ocean on August 3, 1914.
The construction of the canal was completed in 1914, 401 years after Panama was first crossed by Vasco Nez de Balboa. The United States spent almost $375,000,000 (roughly equivalent to $9,169,650,000 now) to finish the project. This was by far the largest American engineering project to date. The canal was formally opened on August 15, 1914, with the passage of the cargo ship SS Ancon.
The opening of Panama Canal in 1914 caused a severe drop in traffic along Chilean ports due to shifts in the maritime trade routes.
Throughout this time, Ernest "Red" Hallen was hired by the Isthmian Canal Commission to document the progress of the work.