OKB-754
From the Metal Gear Wiki
OKB-754 is a research facility similiar to the OKB-812, and was headed by Nikolai Stepanovich Sokolov. The facility was behind the initial development of Dr. Sokolov's revolutionary weapon, the Shagohod. It was the most secret of the OKB labs.
The OKB-754 was destroyed during the Virtuous Mission when Colonel Volgin launched one of the Davy Crockett nuclear shells The Boss had given Volgin after defecting over to the Soviet Union. This was an unintended development of the American Philosophers plans to regain the Legacy, thus forcing the American government to prove that they were not involved by sending in Naked Snake to assassinate The Boss and regain the Philosopher's Legacy once and for all. It was later revealed that the The Boss never really defected at all but was a double-agent working for the government. Her orders were to retrieve the microchip containing the whereabouts of the Philosopher's Legacy, but after the destruction of the OKB-754 there was no turning back, the CIA had taken the incident under consideration and altered their plan so that Snake would have to kill The Boss in order to save the mission.
