Solution Structures of Engineered Vault Particles

Ke Ding; Xing Zhang; Jan Mrazek; Valerie A Kickhoefer; Mason Lai; Hwee L Ng; Otto O Yang; Leonard H Rome; Z Hong Zhou

doi:10.1016/j.str.2018.02.014

Solution Structures of Engineered Vault Particles

Structure. 2018 Apr 3;26(4):619-626.e3. doi: 10.1016/j.str.2018.02.014. Epub 2018 Mar 15.

Authors

Ke Ding¹, Xing Zhang², Jan Mrazek³, Valerie A Kickhoefer⁴, Mason Lai⁵, Hwee L Ng⁶, Otto O Yang⁷, Leonard H Rome⁸, Z Hong Zhou⁹

Affiliations

¹ Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
² California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
³ Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
⁴ Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
⁵ Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
⁶ Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
⁷ California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; Division of Infectious Diseases, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; AIDS Healthcare Foundation, Los Angeles, CA 90028, USA.
⁸ California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
⁹ Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA. Electronic address: hong.zhou@ucla.edu.

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.

Keywords: cellular organelle; cryo-EM; drug delivery; human immunodeficiency virus (HIV); imaging; nanoparticle engineering; protein design; single-particle analysis; structural dynamics; vaccine design.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Amino Acid Sequence
Animals
Baculoviridae / genetics
Baculoviridae / metabolism
Binding Sites
Cloning, Molecular
Crystallography, X-Ray
Drug Delivery Systems / methods*
Gene Expression
Genetic Vectors / chemistry
Genetic Vectors / metabolism
Models, Molecular
Protein Binding
Protein Conformation, alpha-Helical
Protein Conformation, beta-Strand
Protein Engineering / methods*
Protein Interaction Domains and Motifs
Rats
Recombinant Proteins / chemistry
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
Sf9 Cells
Spodoptera
Vault Ribonucleoprotein Particles / chemistry*
Vault Ribonucleoprotein Particles / genetics
Vault Ribonucleoprotein Particles / metabolism
gag Gene Products, Human Immunodeficiency Virus / chemistry*
gag Gene Products, Human Immunodeficiency Virus / genetics
gag Gene Products, Human Immunodeficiency Virus / metabolism

Substances

Recombinant Proteins
Vault Ribonucleoprotein Particles
gag Gene Products, Human Immunodeficiency Virus
major vault protein

Abstract

Publication types

MeSH terms

Substances

Grants and funding