1. Solution Structures of Engineered Vault Particles
- Author
-
Ding, Ke, Zhang, Xing, Mrazek, Jan, Kickhoefer, Valerie A, Lai, Mason, Ng, Hwee L, Yang, Otto O, Rome, Leonard H, and Zhou, Z Hong
- Subjects
Inorganic Chemistry ,Chemical Sciences ,Bioengineering ,Amino Acid Sequence ,Animals ,Baculoviridae ,Binding Sites ,Cloning ,Molecular ,Crystallography ,X-Ray ,Drug Delivery Systems ,Gene Expression ,Genetic Vectors ,Models ,Molecular ,Protein Binding ,Protein Conformation ,alpha-Helical ,Protein Conformation ,beta-Strand ,Protein Engineering ,Protein Interaction Domains and Motifs ,Rats ,Recombinant Proteins ,Sf9 Cells ,Spodoptera ,Vault Ribonucleoprotein Particles ,gag Gene Products ,Human Immunodeficiency Virus ,cellular organelle ,cryo-EM ,drug delivery ,human immunodeficiency virus ,imaging ,nanoparticle engineering ,protein design ,single-particle analysis ,structural dynamics ,vaccine design ,Biological Sciences ,Information and Computing Sciences ,Biophysics ,Biological sciences ,Chemical sciences - Abstract
Prior crystal structures of the vault have provided clues of its structural variability but are non-conclusive due to crystal packing. Here, we obtained vaults by engineering at the N terminus of rat major vault protein (MVP) an HIV-1 Gag protein segment and determined their near-atomic resolution (∼4.8 Å) structures in a solution/non-crystalline environment. The barrel-shaped vaults in solution adopt two conformations, 1 and 2, both with D39 symmetry. From the N to C termini, each MVP monomer has three regions: body, shoulder, and cap. While conformation 1 is identical to one of the crystal structures, the shoulder in conformation 2 is translocated longitudinally up to 10 Å, resulting in an outward-projected cap. Our structures clarify the structural discrepancies in the body region in the prior crystallography models. The vault's drug-delivery potential is highlighted by the internal disposition and structural flexibility of its Gag-loaded N-terminal extension at the barrel waist of the engineered vault.
- Published
- 2018