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Entry Detail
PDB ID:
7EEI
EMDB ID:
Keywords:
Title:
Structure of Rift Valley fever virus RNA-dependent RNA polymerase
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2021-03-18
Release Date:
2021-11-17
Method Details:
Experimental Method:
Resolution:
3.60 Å
Aggregation State:
3D ARRAY
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Replicase
Mutations:K322S
Chain IDs:A
Chain Length:1776
Number of Molecules:1
Biological Source:Rift valley fever virus
Ligand Molecules
Primary Citation
Structure of Rift Valley Fever Virus RNA-Dependent RNA Polymerase.
J.Virol. 96 e0171321 e0171321 (2022)
PMID: 34787453 DOI: 10.1128/JVI.01713-21

Abstact

Rift Valley fever virus (RVFV) belongs to the order Bunyavirales and is the type species of genus Phlebovirus, which accounts for over 50% of family Phenuiviridae species. RVFV is mosquito-borne and causes severe diseases in both humans and livestock, and consists of three segments (S, M, L) in the genome. The L segment encodes an RNA-dependent RNA polymerase (RdRp, L protein) that is responsible for facilitating the replication and transcription of the virus. It is essential for the virus and has multiple drug targets. Here, we established an expression system and purification procedures for full-length L protein, which is composed of an endonuclease domain, RdRp domain, and cap-binding domain. A cryo-EM L protein structure was reported at 3.6 Å resolution. In this first L protein structure of genus Phlebovirus, the priming loop of RVFV L protein is distinctly different from those of other L proteins and undergoes large movements related to its replication role. Structural and biochemical analyses indicate that a single template can induce initiation of RNA synthesis, which is notably enhanced by 5' viral RNA. These findings help advance our understanding of the mechanism of RNA synthesis and provide an important basis for developing antiviral inhibitors. IMPORTANCE The zoonosis RVF virus (RVFV) is one of the most serious arbovirus threats to both human and animal health. RNA-dependent RNA polymerase (RdRp) is a multifunctional enzyme catalyzing genome replication as well as viral transcription, so the RdRp is essential for studying the virus and has multiple drug targets. In our study, we report the structure of RVFV L protein at 3.6 Å resolution by cryo-EM. This is the first L protein structure of genus Phlebovirus. Strikingly, a single template can initiate RNA replication. The structure and assays provide a comprehensive and in-depth understanding of the catalytic and substrate recognition mechanism of RdRp.

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Primary Citation of related structures