Protein Domain : SARS-like ORF8 accessory protein, Ig-like domain IPR046444

Type	Domain
Description	Coronaviruses (CoVs) have a similar genomic structure and encodes four structural proteins (S, E, M and N) and a variable number of accessory proteins. Accessory proteins play an important role in virus-host interactions, especially in antagonizing or regulating host immunity and virus adaptation to the host. There are large variations in the number of accessory proteins (1-10) among coronaviruses. BetaCoVs have 3-5 accessory proteins, except for SARS-CoV and SARS-CoV-2, which possess the largest number of accessory proteins among all coronaviruses (10 and 9, respectively). ORF8 is the most variable accessory protein among those encoded by SARS related coronaviruses (SARSr-CoVs) and is not shared by all members of subgenus Sarbecovirus. SARSr ORF8 accessory proteins are characterized by the presence of an N-terminal hydrophobic signal peptide, a conserved N-glycosylation site, and enough cysteine residues with the potential to form disulfide bonds, drawing their picture as structurally stable potential ER-resident proteins. There is functional overlap between these proteins with involvement in immune modulation, which is probably accomplished through involvement in protein quality control. When ORF8 is exogenously overexpressed in cells, it disrupts IFN-I signaling. Unlike ORF8a/b of SARS-CoV, the SARS-CoV-2 ORF8 downregulates MHC-I in cells.This entry represents the immunoglobulin (Ig)-like domain from SARSr ORF8 [ , , , , ].
Short Name	SARS_ORF8_IG