tetano
Editor, Senior Moderator
Nat Microbiol. 2016 May;1(5). pii: 16029. Epub 2016 Mar 21.
[h=1]The role of the priming loop in Influenza A virus RNA synthesis.[/h] Te Velthuis AJ[SUP]1[/SUP], Robb NC[SUP]2[/SUP], Kapanidis AN[SUP]2[/SUP], Fodor E[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] RNA-dependent RNA polymerases (RdRps) are used by RNA viruses to replicate and transcribe their RNA genomes1. They adopt a closed, right-handed fold with conserved subdomains called palm, fingers, and thumb1,2. Conserved RdRp motifs A-F coordinate the viral RNA template, NTPs, and magnesium ions to facilitate nucleotide condensation1. For the initiation of RNA synthesis, most RdRps use either a primer-dependent or de novo mechanism3. The Influenza A virus RdRp in contrast, uses a capped RNA oligonucleotide to initiate transcription, and a combination of terminal and internal de novo initiation for replication4. To understand how the Influenza A virus RdRp coordinates these processes, we analysed the function of a thumb subdomain β-hairpin using initiation, elongation, and single-molecule FRET assays. Our data shows that this β-hairpin is essential for terminal initiation during replication, but auxiliary for internal initiation and transcription. Analysis of individual residues in the tip of the β-hairpin shows that PB1 proline 651 is critical for efficient RNA synthesis in vitro and in cell culture. Overall, this work advances our understanding of Influenza A virus RNA synthesis and identifies the initiation platform of viral replication.
[h=4]KEYWORDS:[/h] Influenza virus; RNA-dependent RNA polymerase; priming loop; replication; transcription
PMID: 27274864 [PubMed] PMCID: PMC4888940 [Available on 2016-11-01]
[h=1]The role of the priming loop in Influenza A virus RNA synthesis.[/h] Te Velthuis AJ[SUP]1[/SUP], Robb NC[SUP]2[/SUP], Kapanidis AN[SUP]2[/SUP], Fodor E[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] RNA-dependent RNA polymerases (RdRps) are used by RNA viruses to replicate and transcribe their RNA genomes1. They adopt a closed, right-handed fold with conserved subdomains called palm, fingers, and thumb1,2. Conserved RdRp motifs A-F coordinate the viral RNA template, NTPs, and magnesium ions to facilitate nucleotide condensation1. For the initiation of RNA synthesis, most RdRps use either a primer-dependent or de novo mechanism3. The Influenza A virus RdRp in contrast, uses a capped RNA oligonucleotide to initiate transcription, and a combination of terminal and internal de novo initiation for replication4. To understand how the Influenza A virus RdRp coordinates these processes, we analysed the function of a thumb subdomain β-hairpin using initiation, elongation, and single-molecule FRET assays. Our data shows that this β-hairpin is essential for terminal initiation during replication, but auxiliary for internal initiation and transcription. Analysis of individual residues in the tip of the β-hairpin shows that PB1 proline 651 is critical for efficient RNA synthesis in vitro and in cell culture. Overall, this work advances our understanding of Influenza A virus RNA synthesis and identifies the initiation platform of viral replication.
[h=4]KEYWORDS:[/h] Influenza virus; RNA-dependent RNA polymerase; priming loop; replication; transcription
PMID: 27274864 [PubMed] PMCID: PMC4888940 [Available on 2016-11-01]