ORF3d
ORF3d | |||||||
---|---|---|---|---|---|---|---|
Identifiers | |||||||
Organism | |||||||
Symbol | ORF3d | ||||||
UniProt | P0DTG0 | ||||||
|
ORF3d is a
Nomenclature
There has been significant confusion in the scientific literature around the nomenclature used for the
codons) and SARS-CoV-2 (only 22 codons).[4] Exacerbating the confusion, both the 57-codon protein product[5] and the 22-codon protein product[6] have been described to have similar effects as interferon antagonists.[4]
The recommended nomenclature for SARS-CoV-2 uses the term 5' end of ORF3b in SARS-CoV, and uses the term ORF3d for the 57-codon gene.[4]
Comparative genomics
ORF3d is an
SARS-CoV-2 variants with truncations in ORF3d due to the introduction of a stop codon have been identified with relatively high prevalence.[1][7]
conserved and raises the possibility that the gene does not encode a functional protein, despite experimental evidence of protein expression.[8]
Expression
The ORF3d protein has two
amino acid residues long and one 33 residues long, the latter of which is known as ORF3d-2.[1] There is experimental evidence from studies such as ribosome profiling for expression of at least ORF3d-2, without clear evidence for the full-length ORF3d.[1][2]
Function
The function of the ORF3d protein is not known, and it is possible that the gene does not code for a protein with any functional role in the viral life cycle.[8] When expressed under experimental conditions in cell culture, the ORF3d protein appears to be an interferon antagonist.[5]
Robust antibody responses to peptides from ORF3d have been reported in patients recovered from COVID-19.[3]