ABSTRACT The heterotrimeric influenza virus polymerase, containing the PA, PB1 and PB2 proteins, catalyses viral RNA replication and transcription in the nucleus of infected cells. PB1 holds

the polymerase active site1 and reportedly harbours endonuclease activity2, whereas PB2 is responsible for cap binding2,3,4. The PA amino terminus is understood to be the major functional

part of the PA protein and has been implicated in several roles, including endonuclease5 and protease activities6 as well as viral RNA/complementary RNA promoter binding7. Here we report the

2.2 ångström (Å) crystal structure of the N-terminal 197 residues of PA, termed PAN, from an avian influenza H5N1 virus. The PAN structure has an α/β architecture and reveals a bound

assays strongly suggest that PAN holds the endonuclease active site and has critical roles in endonuclease activity of the influenza virus polymerase, rather than PB1. The high conservation

of this endonuclease active site among influenza strains indicates that PAN is an important target for the design of new anti-influenza therapeutics. Access through your institution Buy or

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MOLECULAR BASIS OF HOST-ADAPTATION INTERACTIONS BETWEEN INFLUENZA VIRUS POLYMERASE PB2 SUBUNIT AND ANP32A Article Open access 21 July 2020 STRUCTURES OF H5N1 INFLUENZA POLYMERASE WITH

ANP32B REVEAL MECHANISMS OF GENOME REPLICATION AND HOST ADAPTATION Article Open access 15 May 2024 STRUCTURES OF INFLUENZA A AND B REPLICATION COMPLEXES GIVE INSIGHT INTO AVIAN TO HUMAN HOST

ADAPTATION AND REVEAL A ROLE OF ANP32 AS AN ELECTROSTATIC CHAPERONE FOR THE APO-POLYMERASE Article Open access 19 August 2024 ACCESSION CODES PRIMARY ACCESSIONS PROTEIN DATA BANK * 1WDJ *

2IXS * 3EBJ DATA DEPOSITS Atomic coordinates and structure factors for the reported crystal structure have been deposited with the Protein Data Bank under the accession number 3EBJ.

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Yu for providing the A/goose/Guangdong/1/96 influenza PA gene, R. Zhang and A. Joachimiak for assistance with data collection, and G. G. Brownlee for providing materials and for valuable

advice. This work was supported by the National Natural Science Foundation of China (grant numbers 30599432, 30221003 and 30721003), the Ministry of Science and Technology International

Cooperation Project (2006DFB32420), the Ministry of Science and Technology 863 Project (2006AA02A314 and 2006AA02A322), the Ministry of Science and Technology 973 Project (2006CB504300 and

2007CB914300) and the Medical Research Council (G0700848). AUTHOR INFORMATION Author notes * Puwei Yuan, Mark Bartlam and Zhiyong Lou: These authors contributed equally to this work. AUTHORS

AND AFFILIATIONS * National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China , Puwei Yuan, Shoudeng Chen, Jie Zhou, Xiaojing He, 

Zongyang Lv, Xuemei Li, Zihe Rao & Yingfang Liu * College of Life Sciences and Tianjin Key Laboratory of Protein Science, Nankai University, Tianjin 300071, China Mark Bartlam, Tao Deng 

& Zihe Rao * Laboratory of Structural Biology, Tsinghua University, Beijing 100084, China Zhiyong Lou, Xuemei Li & Zihe Rao * Department of Biological Sciences, National University

of Singapore, Singapore 117543 Ruowen Ge * Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK Tao Deng & Ervin Fodor Authors * Puwei Yuan View author

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Yingfang Liu. SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION This file contains Supplementary Figures S1-S4 with Legends and Supplementary Table T1. (PDF 449 kb) POWERPOINT SLIDES

POWERPOINT SLIDE FOR FIG. 1 POWERPOINT SLIDE FOR FIG. 2 POWERPOINT SLIDE FOR FIG. 3 RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Yuan, P., Bartlam,

M., Lou, Z. _et al._ Crystal structure of an avian influenza polymerase PAN reveals an endonuclease active site. _Nature_ 458, 909–913 (2009). https://doi.org/10.1038/nature07720 Download

citation * Received: 28 November 2008 * Accepted: 12 December 2008 * Published: 04 February 2009 * Issue Date: 16 April 2009 * DOI: https://doi.org/10.1038/nature07720 SHARE THIS ARTICLE

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