title: Crystal Structure of the Core Region of Hantavirus Nucleocapsid Protein Reveals the Mechanism for Ribonucleoprotein Complex Formation.
abstract: Hantaviruses, which belong to the genus Hantavirus in the family Bunyaviridae, infect mammals, including humans, causing either hemorrhagic fever with renal syndrome (HFRS) or hantavirus cardiopulmonary syndrome (HCPS) in humans with high mortality. Hantavirus encodes a nucleocapsid protein (NP) to encapsidate the genome and form a ribonucleoprotein complex (RNP) together with viral polymerase. Here, we report the crystal structure of the core domains of NP (NPcore) encoded by Sin Nombre virus (SNV) and Andes virus (ANDV), which are two representative members that cause HCPS in the New World. The constructs of SNV and ANDV NPcore exclude the N- and C-terminal portions of full polypeptide to obtain stable proteins for crystallographic study. The structure features an N lobe and a C lobe to clamp RNA-binding crevice and exhibits two protruding extensions in both lobes. The positively charged residues located in the RNA-binding crevice play a key role in RNA binding and virus replication. We further demonstrated that the C-terminal helix and the linker region connecting the N-terminal coiled-coil domain and NPcore are essential for hantavirus NP oligomerization through contacts made with two adjacent protomers. Moreover, electron microscopy (EM) visualization of native RNPs extracted from the virions revealed that a monomer-sized NP-RNA complex is the building block of viral RNP. This work provides insight into the formation of hantavirus RNP and provides an understanding of the evolutionary connections that exist among bunyaviruses.
  
  
  OBJECTIVE
  Hantaviruses are distributed across a wide and increasing range of host reservoirs throughout the world. In particular, hantaviruses can be transmitted via aerosols of rodent excreta to humans or from human to human and cause HFRS and HCPS, with mortalities of 15% and 50%, respectively. Hantavirus is therefore listed as a category C pathogen. Hantavirus encodes an NP that plays essential roles both in RNP formation and in multiple biological functions. NP is also the exclusive target for the serological diagnoses. This work reveals the structure of hantavirus NP, furthering the knowledge of hantavirus RNP formation, revealing the relationship between hantavirus NP and serological specificity and raising the potential for the development of new diagnosis and therapeutics targeting hantavirus infection.
authors.affiliation: College of Pharmacy and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Institute of Molecular Science, Chemical Biology and Molecular Engineering Laboratory of Education Ministry, Shanxi University, Taiyuan, China.
authors.forename: Wenming
authors.initials: W
authors.lastname: Wang
authors.affiliation: National Laboratory of Macromolecules, Institute of Biophysics, Chinese Academy of Science, Beijing, China.
authors.forename: Yuna
authors.initials: Y
authors.lastname: Sun
authors.affiliation: College of Pharmacy and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Ma
authors.affiliation: College of Pharmacy and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Pharmacy and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Pharmacy and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
authors.forename: Pi
authors.initials: P
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Shen
authors.affiliation: School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA.
authors.forename: Baobin
authors.initials: B
authors.lastname: Li
authors.affiliation: College of Pharmacy and State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China h.wang@wh.iov.cn louzy@mail.tsinghua.edu.cn.
authors.forename: Hualin
authors.initials: H
authors.lastname: Wang
authors.affiliation: Laboratory of Structural Biology and MOE Laboratory of Protein Science, School of Medicine and Life Sciences, Tsinghua University, Beijing, China Collaborative Innovation Center for Biotherapy, Tsinghua University, Beijing, China h.wang@wh.iov.cn louzy@mail.tsinghua.edu.cn.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Lou
mesh_terms: D018360:Crystallography, X-Ray; D006476:Orthohantavirus / Q000737:chemistry*; D008854:Microscopy, Electron; D008958:Models, Molecular; D019590:Nucleocapsid Proteins / Q000737:chemistry* / Q000648:ultrastructure; D011487:Protein Conformation; D012261:Ribonucleoproteins / Q000737:chemistry* / Q000648:ultrastructure; D029261:Sin Nombre virus / Q000737:chemistry*
chemical_list: D019590:Nucleocapsid Proteins; D012261:Ribonucleoproteins