The cap-snatching endonuclease of influenza virus polymerase resides in the PA subunit

@article{Dias2009TheCE,
  title={The cap-snatching endonuclease of influenza virus polymerase resides in the PA subunit},
  author={Alexandre Dias and Denis Bouvier and Thibaut Cr{\'e}pin and Andrew A. McCarthy and Darren J Hart and Florence Baudin and Stephen Cusack and Rob W. H. Ruigrok},
  journal={Nature},
  year={2009},
  volume={458},
  pages={914-918}
}
The influenza virus polymerase, a heterotrimer composed of three subunits, PA, PB1 and PB2, is responsible for replication and transcription of the eight separate segments of the viral RNA genome in the nuclei of infected cells. The polymerase synthesizes viral messenger RNAs using short capped primers derived from cellular transcripts by a unique 'cap-snatching' mechanism. The PB2 subunit binds the 5′ cap of host pre-mRNAs, which are subsequently cleaved after 10–13 nucleotides by the viral… Expand
Characterization of PA-N terminal domain of Influenza A polymerase reveals sequence specific RNA cleavage
TLDR
It is shown that PA is a sequence selective endonuclease with distinct preference to cleave at the 3′ end of a guanine (G) base in RNA. Expand
Role of the PB2 627 Domain in Influenza A Virus Polymerase Function
TLDR
It is shown that the PB2 627 domain is essential for the accumulation of the cRNA replicative intermediate in infected cells, furthering the understanding of the role of the PB1 and PA subunit in transcription and replication of the influenza virus RNA genome. Expand
Mutational and Metal Binding Analysis of the Endonuclease Domain of the Influenza Virus Polymerase PA Subunit
TLDR
The results validate the use of the isolated endonuclease domain in a drug-design process for new anti-influenza virus compounds and confirm the importance of a number of active-site residues and identify some residues that may be involved in the positioning of the RNA substrate in the active site. Expand
Crystal structure of the RNA-dependent RNA polymerase from influenza C virus
TLDR
The structure of apo-FluPol is reported, solved by X-ray crystallography to 3.9 Å, revealing a new ‘closed’ conformation that captures FluPol in a closed, transcription pre-activation state, and aids the understanding of the mechanisms controlling transcription and genome replication. Expand
Endonuclease substrate selectivity characterized with full-length PA of influenza A virus polymerase.
TLDR
An improved in vitro assay was able to demonstrate the minimal substrate size and sequence selectivity of the PA protein, which is crucial information for inhibitor design, and confirmed the observed endonuclease activity of the full-length PA with a FRET-based assay. Expand
Bunyaviridae RNA Polymerases (L-Protein) Have an N-Terminal, Influenza-Like Endonuclease Domain, Essential for Viral Cap-Dependent Transcription
TLDR
Structurally and functionally characterize a similar endonuclease in La Crosse orthobunyavirus (LACV) L-protein and suggest that L-proteins might be architecturally, and functionally equivalent to a concatemer of the three orthomyxovirus polymerase subunits in the order PA-PB1-PB2. Expand
Influenza A Virus Polymerase: Structural Insights into Replication and Host Adaptation Mechanisms*
TLDR
The heterotrimeric RNA-dependent RNA polymerase of influenza viruses catalyzes RNA replication and transcription activities in infected cell nuclei, and the activity is highly host- and cell type-specific, being dependent on the identity of a few key amino acid positions in the different subunits. Expand
Influenza Polymerase Can Adopt an Alternative Configuration Involving a Radical Repacking of PB2 Domains
TLDR
A FluB polymerase structure with a bound complementary cRNA 5′ end that exhibits a major rearrangement of the subdomains within the C-terminal two-thirds of PB2 (PB2-C) is presented. Expand
Structural insights into RNA synthesis by the influenza virus transcription-replication machine.
TLDR
This review focusses on the new insights that recent crystal structures have given into the detailed molecular mechanisms by which the polymerase performs both transcription and replication of the vRNA genome. Expand
Structure of influenza A polymerase bound to the viral RNA promoter
TLDR
The crystal structure of the heterotrimeric bat influenza A polymerase, comprising subunits PA, PB1 and PB2, bound to its viral RNA promoter is presented, laying the basis for an atomic-level mechanistic understanding of the many functions of influenza polymerase and opens new opportunities for anti-influenza drug design. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 34 REFERENCES
The active sites of the influenza cap‐dependent endonuclease are on different polymerase subunits
TLDR
A molecular map of the five known essential active sites of the influenza viral polymerase is provided, showing that at least one of the tryptophans functions in cap binding, indicating that this active site is probably similar to that of other known cap‐binding proteins. Expand
The structural basis for cap binding by influenza virus polymerase subunit PB2
TLDR
Binding and functional studies with point mutants confirm that the identified site is essential for cap binding in vitro and cap-dependent transcription in vivo by the trimeric polymerase complex, and will allow efficient structure-based design of new anti-influenza compounds inhibiting viral transcription. Expand
Influenza A virus RNA polymerase subunit PB2 is the endonuclease which cleaves host cell mRNA and functions only as the trimeric enzyme.
TLDR
The results suggest that viral PB2 protein is the endonuclease that cleaves host cell mRNA to produce the primer used to initiate transcription; however, association with the other two enzyme subunits seems to be required for this PB2 function. Expand
A Single Amino Acid Mutation in the PA Subunit of the Influenza Virus RNA Polymerase Inhibits Endonucleolytic Cleavage of Capped RNAs
TLDR
It is demonstrated that the PA subunit of influenza A virus RNA-dependent RNA polymerase is required not only for replication but also for transcription of viral RNA. Expand
A unique cap(m7GpppXm)-dependent influenza virion endonuclease cleaves capped RNAs to generate the primers that initiate viral RNA transcription
TLDR
It is shown that virions and purified viral cores contain a unique endonuclease that cleaves RNAs containing a 5' methylated cap structure preferentially at purine residues 10 to 14 nucleotides from the cap, generating fragments with 3'-terminal hydroxyl groups. Expand
RNA and DNA Hydrolysis Are Catalyzed by the Influenza Virus Endonuclease*
TLDR
It is demonstrated that the 2′-hydroxy groups are not essential for binding and cleavage of nucleic acids by the influenza virus endonuclease, but small differences of the nucleic acid conformation in the end onuclease active site can influence the overall rate of hydrolysis. Expand
Minimum molecular architectures for transcription and replication of the influenza virus
TLDR
It is proposed that the catalytic specificity of PB1 subunit is modulated to the transcriptase by binding PB2 or the replicase by interaction with PA. Expand
Crucial role of CA cleavage sites in the cap‐snatching mechanism for initiating viral mRNA synthesis
TLDR
It is demonstrated that the influenza viral polymerase, which is assembled in human cells using recombinant proteins, effectively uses only CA‐terminated capped fragments as primers for viral mRNA synthesis in vitro, providing the first in vitro system that mirrors the cap‐snatching process occurring in vivo during virus infection. Expand
Two Aromatic Residues in the PB2 Subunit of Influenza A RNA Polymerase Are Crucial for Cap Binding*
TLDR
The results favor a similar mechanism of cap binding by the influenza RNA polymerase as in the evolutionary unrelated VP39, eIF4E, and CBP20. Expand
Structure of influenza virus RNP. I. Influenza virus nucleoprotein melts secondary structure in panhandle RNA and exposes the bases to the solvent.
TLDR
The results suggest that the nucleoprotein binds to the vRNA backbone without apparent sequence specificity, exposing the bases to the outside and melting all secondary structure, and the viral polymerase may transcribe the RNA without the need for dissociating theucleoprotein and without being stopped by RNA secondary structure. Expand
...
1
2
3
4
...