ORF9b

ORF9b

Structure of ORF9b protein

ORF9b is a protein encoded by the SARS-CoV virus, which is responsible for the Severe Acute Respiratory Syndrome (SARS). This protein is one of the accessory proteins of the virus, which are not essential for replication but may play roles in modulating the host's immune response and enhancing viral pathogenicity.

Structure

ORF9b is a small protein that is encoded within the nucleocapsid (N) gene of the SARS-CoV genome. The structure of ORF9b has been determined using X-ray crystallography, revealing a compact, dimeric form. The protein is composed of a series of alpha helices and beta sheets, forming a unique fold that is distinct from other known viral proteins.

Function

The exact function of ORF9b in the viral life cycle is not fully understood. However, studies suggest that ORF9b may interact with host cell proteins to modulate the innate immune response. It has been proposed that ORF9b can interfere with the host's interferon signaling pathways, potentially aiding the virus in evading immune detection.

Role in Pathogenicity

ORF9b, like other accessory proteins of SARS-CoV, is not required for viral replication in vitro. However, it may contribute to the virus's ability to cause disease in vivo. By modulating the host's immune response, ORF9b could enhance viral survival and replication within the host, leading to more severe disease outcomes.

Related pages

• SARS-CoV
• SARS-CoV-2
• Viral protein
• Immune evasion