Article
K.S. collected X-ray diffraction data, determined and refined the structure, analysed the
structure, and reviewed the manuscript. Y.W. conceptualized the project, expressed and
purified proteins, performed protein pull-down experiments and the pseudovirus entry assay,
and reviewed the manuscript. C.L. performed protein pull-down experiments and the
pseudovirus entry assay, and reviewed the manuscript. H.A. provided resources, analysed the
structure, and reviewed the manuscript. Q.G. performed protein pull-down experiments and the
pseudovirus entry assay, and reviewed the manuscript. A.A. expressed and purified proteins,
and reviewed the manuscript. F.L. conceptualized and supervised the project, provided
resources, guided the experiments and data analysis, and wrote the manuscript.
Competing interests The authors declare no competing interests.Additional information
Supplementary information is available for this paper at https://doi.org/10.1038/s41586-020-
2179-y.
Correspondence and requests for materials should be addressed to F.L.
Peer review information Nature thanks Lijun Rong and the other, anonymous, reviewer(s) for
their contribution to the peer review of this work.
Reprints and permissions information is available at http://www.nature.com/reprints.