Article | Published:

Structure of influenza A polymerase bound to the viral RNA promoter

Nature volume 516, pages 355360 (18 December 2014) | Download Citation

Subjects

Abstract

The influenza virus polymerase transcribes or replicates the segmented RNA genome (viral RNA) into viral messenger RNA or full-length copies. To initiate RNA synthesis, the polymerase binds to the conserved 3′ and 5′ extremities of the viral RNA. Here we present the crystal structure of the heterotrimeric bat influenza A polymerase, comprising subunits PA, PB1 and PB2, bound to its viral RNA promoter. PB1 contains a canonical RNA polymerase fold that is stabilized by large interfaces with PA and PB2. The PA endonuclease and the PB2 cap-binding domain, involved in transcription by cap-snatching, form protrusions facing each other across a solvent channel. The 5′ extremity of the promoter folds into a compact hook that is bound in a pocket formed by PB1 and PA close to the polymerase active site. This structure lays the basis for an atomic-level mechanistic understanding of the many functions of influenza polymerase, and opens new opportunities for anti-influenza drug design.

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Accessions

Primary accessions

Protein Data Bank

Data deposits

Structure factors and coordinates for Bat FluA have been deposited in the Protein Data Bank (PDB) under accession 4WSB.

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Acknowledgements

We thank members of the ESRF-EMBL Joint Structural Biology Group for access to European Synchrotron Radiation Facility (ESRF) beamlines, staff of the European Molecular Biology Laboratory (EMBL) eukaryotic expression and high-throughput crystallization facilities within the Partnership for Structural Biology (PSB), D. Hart for help with construct design, and H. Malet for electron microscopy. This work was supported by ERC Advanced Grant V-RNA (322586) to S.C.

Author information

Author notes

    • Alexander Pflug
    • , Delphine Guilligay
    •  & Stefan Reich

    These authors contributed equally to this work.

Affiliations

  1. European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France

    • Alexander Pflug
    • , Delphine Guilligay
    • , Stefan Reich
    •  & Stephen Cusack
  2. University Grenoble Alpes-Centre National de la Recherche Scientifique-EMBL Unit of Virus Host-Cell Interactions, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France

    • Alexander Pflug
    • , Delphine Guilligay
    • , Stefan Reich
    •  & Stephen Cusack

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Contributions

A.P. did protein expression, purification and crystallization, with help from S.R. and D.G. who also did activity assays. A.P. did X-ray data collection and, together with S.C., did crystallographic analysis. S.C. supervised the project and wrote the paper with input from the other authors.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Stephen Cusack.

Extended data

Supplementary information

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  1. 1.

    Supplementary Information

    This file contains Supplementary Figure 1, Supplementary Discussions and Supplementary References.

Videos

  1. 1.

    360° rotation of bat FluA structure in ribbon representation about the vertical axis

    View and colouring as in Fig. 1

  2. 2.

    360° rotation of bat FluA structure in surface representation about the vertical axis

    View and colouring as in Fig. 1.

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DOI

https://doi.org/10.1038/nature14008

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