Publication Date:
2008-07-11
Description:
The recent emergence of highly pathogenic avian influenza A virus strains with subtype H5N1 pose a global threat to human health. Elucidation of the underlying mechanisms of viral replication is critical for development of anti-influenza virus drugs. The influenza RNA-dependent RNA polymerase (RdRp) heterotrimer has crucial roles in viral RNA replication and transcription. It contains three proteins: PA, PB1 and PB2. PB1 harbours polymerase and endonuclease activities and PB2 is responsible for cap binding; PA is implicated in RNA replication and proteolytic activity, although its function is less clearly defined. Here we report the 2.9 angstrom structure of avian H5N1 influenza A virus PA (PA(C), residues 257-716) in complex with the PA-binding region of PB1 (PB1(N), residues 1-25). PA(C) has a fold resembling a dragon's head with PB1(N) clamped into its open 'jaws'. PB1(N) is a known inhibitor that blocks assembly of the polymerase heterotrimer and abolishes viral replication. Our structure provides details for the binding of PB1(N) to PA(C) at the atomic level, demonstrating a potential target for novel anti-influenza therapeutics. We also discuss a potential nucleotide binding site and the roles of some known residues involved in polymerase activity. Furthermore, to explore the role of PA in viral replication and transcription, we propose a model for the influenza RdRp heterotrimer by comparing PA(C) with the lambda3 reovirus polymerase structure, and docking the PA(C) structure into an available low resolution electron microscopy map.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉He, Xiaojing -- Zhou, Jie -- Bartlam, Mark -- Zhang, Rongguang -- Ma, Jianyuan -- Lou, Zhiyong -- Li, Xuemei -- Li, Jingjing -- Joachimiak, Andrzej -- Zeng, Zonghao -- Ge, Ruowen -- Rao, Zihe -- Liu, Yingfang -- England -- Nature. 2008 Aug 28;454(7208):1123-6. doi: 10.1038/nature07120. Epub 2008 Jul 9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18615018" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Binding Sites
;
Birds/*virology
;
Crystallography, X-Ray
;
Influenza A Virus, H5N1 Subtype/*enzymology
;
Models, Molecular
;
Multienzyme Complexes/chemistry/metabolism
;
Nucleotides/metabolism
;
Peptide Fragments/chemistry/metabolism
;
Protein Binding
;
Protein Structure, Quaternary
;
RNA Replicase/*chemistry/metabolism
;
Viral Proteins/*chemistry/*metabolism
;
Virus Replication
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
