Cryo-EM imaging of vaults and vault-like particles

The vault is a large 13 MDa ribonucleoprotein particle that is present in abundant copy numbers and has a nearly ubiquitous distribution among eukaryotic cells. The strong conservation of morphology and composition of the vault across species is an indication of an important cellular function, and recently vaults have been implicated in multidrug resistance in certain cancer cells. We have published several cryo-electron microscopy structural studies of the vault isolated from rat and knockout mice. The structures reveal a large internal cavity in the vault and suggest a role for the particle in either macromolecular transport or sequestration. Here we present our latest results on the structure of recombinantly produced vaultlike particles with various protein compositions.