Isolating a trimer intermediate in the self-assembly of E2 protein cage.
Understanding the self-assembly mechanism of caged proteins provides clues to develop their potential applications in nanotechnology, such as a nanoscale drug delivery system. The E2 protein from  Bacillus stearothermophilus , with a virus-like caged structure, has drawn much attention for its potential application as a nanocapsule. To investigate its self-assembly process from subunits to a spherical protein cage, we truncate the C-terminus of the E2 subunit. The redesigned protein subunit shows dynamic transition between monomer and trimer, but not the integrate 60-mer. The results indicate the role of the trimer as the intermediate and building block during the self-assembly of the E2 protein cage. In combination with the molecular dynamics simulations results, we conclude that the C-terminus modulates the self-assembly of the E2 protein cage from trimer to 60-mer. This investigation elucidates the role of the intersubunit interactions in engineering other functionalities in other caged structure proteins.
Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637457.
Tao
T
Peng
Hwankyu
H
Lee
Sierin
S
Lim
D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D002942:Circular Dichroism; D001411:Geobacillus stearothermophilus / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D050505:Mutant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D053769:Nanocapsules / Q000737:chemistry*; D036103:Nanotechnology; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D001426:Bacterial Proteins; D050505:Mutant Proteins; D053769:Nanocapsules; D011994:Recombinant Proteins