Dr. Phoebe Stewart's lab worked with the Rome lab to carry out a reconstruction of the vault particle from images gathered by cryo-electron microscopy (cryo-EM). Lawrence Kong and Amara Siva led the initial reconstruction efforts and later the work was extended by Yeshi Mikyas and Miriam Makabi. Vaults were purified and individual particles were quick frozen in liquid ethane and viewed under the EM. Images were captured with a digital camera and analyzed using special image construction software. The raw EM vault images are shown (figure 1) in various orientations from end to side views.
Over 1300 particle images were combined to produce the high resolution structure of the vault. This structure (figure 2) reveals a smooth outer shell with a barrel-shaped midsection and two protruding caps.
A slice through the particle reveals the hollow inside (figure 3).
As seen in these raw cryo-EM vault images (figure 4), the vault is large enough to enclose particles such as ribosomes. The image below shows a slice through the center of the vault and two ribosomes are illustrated at the same magnification.