NSP1
(cellular saboteur)
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• Degrades host mRNA, blocks host translation and innate immune response
(21).
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The sabotage forces the infected cell to make more virus proteins and
prevents it from assembling antiviral proteins that could stop the
virus.
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NSP2
(mystery protein)
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• Binds with prohibitin proteins (21).
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Stabilizing mutation of mysterious NSP2 has made SARS-CoV-2 more
contagious than SARS-CoV (111).
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NSP3
(large multi-domain transmembrane protein)
(untagging and cutting)
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• Interact with N protein (through ubiquitin-like 1 and glutamic
acid-rich acidic domains) (21,22).
• Promotes cytokine expression (through ADP-ribose-1’-phosphatase
domain) (21)
• Cleaves viral polyprotein and blocks host innate immune response
(through papain-like protease/Deubiquitinase domain) (21)
• Binds oligoneucleotides known to form G-quadruplexes (by SARS-unique
domain) (22)
• Nucleic acid chaperon function (by nucleic acid binding domain) (22)
• Putative metal binding by transmembrane domains (22)
• Unknown function (Ubiquitin-like 2, G2M, Y domains) (21)
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Modifies proteins of the infected cells. Healthy cell tags old proteins
for destruction. But the coronavirus can change the balance of proteins
and possibly reducing the cell’s ability to fight the virus by removing
the tags.
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NSP4 (transmembrane scaffold protein)
(bubble marker)
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Responsible for double-membrane vesicles assembly (21)
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Inside the vesicles, virus replication can be processed without host
recognition.
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NSP5 (main protease)
(protein scissor)
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Cleaves viral polyprotein (21)
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Cuts free other NSPs to carry out their own jobs.
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NSP6 (transmembrane scaffold protein)
(bubble factory)
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Able to proliferate membrane, induces perinuclear vesicles localization
(112)
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Virus replication inside the vesicles avoid host recognition.
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NSP7
(copy assistant)
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Acts as clamp for RNA polymerase by forming complex with NSP8 (21)
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Helps NSP12 to make new copies of the RNA genome.
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NSP8
(copy assistant)
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Acts as clamp for RNA polymerase by forming complex with NSP7 (21)
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Helps NSP12 to make new copies of the RNA genome
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NSP9
(interest on nucleus)
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RNA binding protein (21)
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May infiltrate tiny channels in the infected cell’s nucleus to influence
the movement of molecules in and out of the nucleus. Host cells have
antiviral proteins that find viral RNA and shred it.
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NSP10
(genetic camouflage)
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Forms heterodimer with NSP14 & NSP16 to stimulate viral exoribonuclease
and 2’-O-methyltransferase respectively (21)
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Involves camouflaging the virus’s genes so that they do not get
attacked.
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NSP11
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Short peptide at the end of ORF1a (49)
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NSP11 of ORF1a overlaps part of the same sequence of ORF1b in RNA genome
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NSP12
(copy machine)
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RNA-dependent RNA polymerase (21)
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Assembles genetic letters into new virus genomes. Virus RNA is wound
into intricate twists and turns.
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NSP13
(unwinding)
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RNA helicase domain and RNA 5’ triphosphatase activity (21)
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Responsible for unwinding virus RNA. Therefore, other proteins can read
its sequence and make new copies.
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NSP14
(proof-reader)
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• N7 Methyltransferase activity to add 5’ cap to viral RNAs (21)
• Viral exoribonuclease activity as proofreading of viral genome (21)
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NSP12 duplicates the coronavirus genome, it sometimes adds a wrong
letter to the new copy. NSP14 cuts out these errors, so that the correct
genetic letter can be added instead.
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NSP15
(cleaning up)
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Viral endoribonuclease (21)
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Chops up leftover virus RNA to hide from the infected cell’s antiviral
defences.
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NSP16
(camouflage assistant)
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2’-O-methyltransferase activity to shield viral RNA from melanoma
differentiation associated protein 5 (21)
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Helps to camouflage the virus’s genes.
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