RNA-directed RNA polymerase complex

Definition

Target type: cellularcomponent

A protein complex that possesses RNA-directed RNA polymerase activity. [GOC:mah]

The RNA-directed RNA polymerase (RdRp) complex is a multi-protein assembly responsible for the replication of RNA viruses. It is a dynamic and intricate structure that undergoes conformational changes during the various stages of the viral replication cycle. The cellular component of the RdRp complex can vary depending on the specific virus, but it typically includes the following elements:

**1. Viral RNA Polymerase:** This is the core catalytic subunit of the RdRp complex. It possesses the enzymatic activity required for synthesizing new RNA strands using a template RNA molecule. The polymerase is a highly conserved protein across RNA viruses, with variations in its structure and function influencing viral replication efficiency and host tropism.

**2. Viral RNA-Dependent RNA Helicase:** Many RNA viruses encode a helicase protein, which functions to unwind double-stranded RNA molecules during replication. This is essential for providing access to the template RNA for the polymerase, allowing efficient synthesis of new viral RNA. Helicases typically possess a conserved ATP-binding site and are essential for the overall replication process.

**3. Viral Capsid Proteins:** In some viruses, capsid proteins are part of the RdRp complex, serving as a protective shell around the viral genome and polymerase. This assembly can also influence the interaction of the complex with cellular components and facilitate its transport within the infected cell.

**4. Cellular Factors:** RNA viruses often exploit cellular factors to enhance their replication. For instance, some viruses recruit host proteins that promote the assembly and stability of the RdRp complex, while others use cellular enzymes to modify the viral RNA, enhancing its translation or replication.

**5. Viral Accessory Proteins:** Several RNA viruses encode accessory proteins that regulate various aspects of the replication cycle, including the recruitment of cellular factors, the formation of viral replication compartments, and the evasion of host immune responses. These proteins can also play roles in the assembly and stability of the RdRp complex.

The specific composition and organization of the RdRp complex can vary significantly between different viral families and species. However, understanding the cellular components and their roles within the complex is crucial for developing antiviral therapies that target viral replication. By inhibiting the assembly, activity, or stability of the RdRp complex, antiviral drugs can effectively block viral propagation and prevent disease.'
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Proteins (1)

Compounds (28)