pfam16348: CoV_NSP4_C (This model is not part of the current CDD release)
Coronavirus replicase NSP4, C-terminal
This is the C-terminal domain of the coronavirus nonstructural protein 4 (NSP4). NSP4 is encoded by ORF1a/1ab and proteolytically released from the pp1a/1ab polyprotein. It is a membrane-spanning protein which is thought to anchor the viral replication-transcription complex (RTC) to modified endoplasmic reticulum membranes. This predominantly alpha-helical domain may be involved in protein-protein interactions. It has been shown that in Betacoronavirus, the coexpression of NSP3 and NSP4 results in a membrane rearrangement to induce double-membrane vesicles (DMVs) and convoluted membranes (CMs), playing a critical role in SARS-CoV replication. There are two well conserved amino acid residues (H120 and F121) in NSP4 among Betacoronavirus, essential for membrane rearrangements during interaction with NSP3.
Jiyao W et al.(2023). "The conserved domain database in 2023.",