sb9b00019_si_002.mov (4.42 MB)
Construction of a Quadrangular Tetramer and a Cage-Like Hexamer from Three-Helix Bundle-Linked Fusion Proteins
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posted on 2019-04-09, 00:00 authored by Takaaki Miyamoto, Yugo Hayashi, Keito Yoshida, Hiroki Watanabe, Takayuki Uchihashi, Kento Yonezawa, Nobutaka Shimizu, Hironari Kamikubo, Shun HirotaSelf-assembled protein nanostructures
have gained interest, owing
to their potential applications in biomaterials; however, successful
design and construction of protein nanostructures are limited. Herein,
we constructed fusion protein 1 by linking the C-terminus
of a dimerization domain and the N-terminus of another dimerization
domain with a three-helix bundle protein, where it self-assembled
mainly into tetramers. By replacing the C-terminal dimerization domain
of 1 with a trimerization domain (fusion protein 2), hexamers were mainly obtained. According to ab
initio structural models reconstructed from the small-angle
X-ray scattering data, the tetramer of 1 and hexamer
of 2 adopted quadrangle and cage-like structures, respectively,
although they were combinations of different conformations. High-speed
atomic force microscopy observations indicated that the tetramer and
hexamer exhibit conformational dynamics. These results show that the
present method utilizing three-helix bundle-linked fusion proteins
is useful in the construction of protein nanostructures.