Biochemical, biophysical and preliminary X-ray crystallographic analyses of the fusion core of Sendai virus F protein.
It is emerging that enveloped viruses may adopt a unique entry/fusion mechanism; in paramyxoviruses, including Sendai virus (SeV), the attachment protein HN (or its homologue H or G) binds a cellular receptor which triggers conformational changes of its fusion protein, F. There are at least three conformations of the F protein in the current fusion model: the pre-fusion native conformation, the pre-hairpin intermediate conformation and the post-fusion coiled-coil conformation. The fusion mechanism of SeV, a member of the Paramyxoviridae family, has been well established and several structural and functional domains or modules have been proposed from studies of its F protein. However, biochemical and biophysical studies of the heptad-repeat (HR) regions (HR1 and HR2) have not been systematically carried out. HR1 and HR2 strongly interact with each other to form a stable six-helix coiled-coil bundle as the post-fusion conformation. In this study, a single-chain HR1-linker-HR2 protein of SeV was prepared in an Escherichia coli expression system and biochemical and biophysical analyses showed it to form a typical six-helix coiled-coil bundle; its trigonal crystals diffracted X-rays to 2.5 A resolution. The crystal structure will help to reveal the structural requirements of the post-fusion coiled-coil conformation of SeV F protein.
Wang
Xiaojia
X
College of Animal Medicine, China Agricultural University, Beijing 100094, People's Republic of China.
Xu
Yanhui
Y
Cole
David K
DK
Lou
Zhiyong
Z
Liu
Yiwei
Y
Rao
Zihe
Z
Wang
Ming
M
Gao
George F
GF
D000595:Amino Acid Sequence; D055592:Biophysical Phenomena; D001703:Biophysics; D003460:Crystallization; D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D029082:Sendai virus / Q000235:genetics / Q000378:metabolism; D014760:Viral Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics
D014760:Viral Fusion Proteins