3UB0

Crystal structure of the nonstructural protein 7 and 8 complex of Feline Coronavirus


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Nonstructural proteins 7 and 8 of feline coronavirus form a 2:1 heterotrimer that exhibits primer-independent RNA polymerase activity.

Xiao, Y.Ma, Q.Restle, T.Shang, W.Svergun, D.I.Ponnusamy, R.Sczakiel, G.Hilgenfeld, R.

(2012) J Virol 86: 4444-4454

  • DOI: 10.1128/JVI.06635-11
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Nonstructural proteins 7 and 8 of severe acute respiratory syndrome coronavirus (SARS-CoV) have previously been shown by X-ray crystallography to form an 8:8 hexadecamer. In addition, it has been demonstrated that N-terminally His(6)-tagged SARS-CoV ...

    Nonstructural proteins 7 and 8 of severe acute respiratory syndrome coronavirus (SARS-CoV) have previously been shown by X-ray crystallography to form an 8:8 hexadecamer. In addition, it has been demonstrated that N-terminally His(6)-tagged SARS-CoV Nsp8 is a primase able to synthesize RNA oligonucleotides with a length of up to 6 nucleotides. We present here the 2.6-Å crystal structure of the feline coronavirus (FCoV) Nsp7:Nsp8 complex, which is a 2:1 heterotrimer containing two copies of the α-helical Nsp7 with conformational differences between them, and one copy of Nsp8 that consists of an α/β domain and a long-α-helix domain. The same stoichiometry is found for the Nsp7:Nsp8 complex in solution, as demonstrated by chemical cross-linking, size exclusion chromatography, and small-angle X-ray scattering. Furthermore, we show that FCoV Nsp8, like its SARS-CoV counterpart, is able to synthesize short oligoribonucleotides of up to 6 nucleotides in length when carrying an N-terminal His(6) tag. Remarkably, the same protein harboring the sequence GPLG instead of the His(6) tag at its N terminus exhibits a substantially increased, primer-independent RNA polymerase activity. Upon addition of Nsp7, the RNA polymerase activity is further enhanced so that RNA up to template length (67 nucleotides) can be synthesized. Further, we show that the unprocessed intermediate polyprotein Nsp7-10 of human coronavirus (HCoV) 229E is also capable of synthesizing oligoribonucleotides up to a chain length of six. These results indicate that in case of FCoV as well as of HCoV 229E, the formation of a hexadecameric Nsp7:Nsp8 complex is not necessary for RNA polymerase activity. Further, the FCoV Nsp7:Nsp8 complex functions as a noncanonical RNA polymerase capable of synthesizing RNA of up to template length.


    Organizational Affiliation

    Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Lübeck, Germany.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Non-structural protein 7, nsp7B, C, E, F87Feline infectious peritonitis virus (strain 79-1146)Mutation(s): 0 
Gene Names: rep1a-1b
EC: 3.4.19.12 (UniProt), 3.4.22 (UniProt), 2.7.7.48 (UniProt), 3.6.4.12 (UniProt), 3.6.4.13 (UniProt), 3.1.13 (UniProt), 3.1 (UniProt), 2.1.1 (UniProt)
Find proteins for Q98VG9 (Feline coronavirus (strain FIPV WSU-79/1146))
Explore Q98VG9 
Go to UniProtKB:  Q98VG9
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Non-structural protein 6, nsp6,A, D199Feline infectious peritonitis virus (strain 79-1146)Mutation(s): 0 
Gene Names: rep1a-1b
EC: 3.4.19.12 (UniProt), 3.4.22 (UniProt), 2.7.7.48 (UniProt), 3.6.4.12 (UniProt), 3.6.4.13 (UniProt), 3.1.13 (UniProt), 3.1 (UniProt), 2.1.1 (UniProt)
Find proteins for Q98VG9 (Feline coronavirus (strain FIPV WSU-79/1146))
Explore Q98VG9 
Go to UniProtKB:  Q98VG9
Protein Feature View
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A,DL-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.60 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.206 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 121.454α = 90
b = 160.301β = 90
c = 102.66γ = 90
Software Package:
Software NamePurpose
MAR345data collection
SHELXDphasing
SHELXEmodel building
BUSTERrefinement
XDSdata reduction
XDSdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-02-22
    Type: Initial release
  • Version 1.1: 2012-10-17
    Changes: Database references
  • Version 1.2: 2017-11-08
    Changes: Refinement description