title: Crystal structure of severe acute respiratory syndrome coronavirus spike protein fusion core.
abstract: Severe acute respiratory syndrome coronavirus is a newly emergent virus responsible for a recent outbreak of an atypical pneumonia. The coronavirus spike protein, an enveloped glycoprotein essential for viral entry, belongs to the class I fusion proteins and is characterized by the presence of two heptad repeat (HR) regions, HR1 and HR2. These two regions are understood to form a fusion-active conformation similar to those of other typical viral fusion proteins. This hairpin structure likely juxtaposes the viral and cellular membranes, thus facilitating membrane fusion and subsequent viral entry. The fusion core protein of severe acute respiratory syndrome coronavirus spike protein was crystallized, and the structure was determined at 2.8 A of resolution. The fusion core is a six-helix bundle with three HR2 helices packed against the hydrophobic grooves on the surface of central coiled coil formed by three parallel HR1 helices in an oblique antiparallel manner. This structure shares significant similarity with the fusion core structure of mouse hepatitis virus spike protein and other viral fusion proteins, suggesting a conserved mechanism of membrane fusion. Drug discovery strategies aimed at inhibiting viral entry by blocking hairpin formation, which have been successfully used in human immunodeficiency virus 1 inhibitor development, may be applicable to the inhibition of severe acute respiratory syndrome coronavirus on the basis of structural information provided here. The relatively deep grooves on the surface of the central coiled coil will be a good target site for the design of viral fusion inhibitors.
authors.affiliation: Laboratory of Structural Biology, Tsinghua University, Beijing 100084 and National Laboratory of Bio-Macromolecules, Institute of Biophysics, Beijing 100101, China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Xu
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Lou
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Liu
authors.forename: Hai
authors.initials: H
authors.lastname: Pang
authors.forename: Po
authors.initials: P
authors.lastname: Tien
authors.forename: George F
authors.initials: GF
authors.lastname: Gao
authors.forename: Zihe
authors.initials: Z
authors.lastname: Rao
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000494:pharmacology; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D019281:Dimerization; D008562:Membrane Glycoproteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D045473:Severe acute respiratory syndrome-related coronavirus / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins / Q000737:chemistry*
chemical_list: D000998:Antiviral Agents; D008562:Membrane Glycoproteins; D010455:Peptides; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins