Table 1. Severe acute respiratory syndrome (SARS)-CoV-2 proteins.

SARS-CoV-2 proteins	General impact
Structural proteins
S (spike)	Spike protein, mediates binding to ACE2, fusion with host membrane Surface glycoprotein, needs to be processed by cellular protease TMPRSS2 (Gordon et al., 2020)
M (membrane)	Membrane glycoprotein, the predominant component of the envelope A major driver for virus assembly and budding (Gordon et al., 2020)
E (envelope)	Envelope protein, involved in virus morphogenesis and assembly Coexpression of M and E is sufficient for virus-like particle formation and release (Gordon et al., 2020)
N (nucleocapsid)	Nucleocapsid phosphoprotein binds to RNA genome (Gordon et al., 2020)
Nonstructural proteins
nsp1	Leader sequence, suppresses host antiviral response Antagonizes interferon induction to suppress host antiviral response (Gordon et al., 2020)
nsp2	Interferes with host cell signaling, including cell cycle, cell-death pathways, and cell differentiation May serve as an adaptor for nsp3 Not essential for virus replication, but deletion of nsp2 diminishes viral growth and RNA synthesis (Gordon et al., 2020; Procko, 2020)
nsp3	nsp3–nsp4–nsp6 complex involved in viral replication Functions as papain-like protease (Gordon et al., 2020)
nsp4	nsp3–nsp4–nsp6 complex involved in viral replication (Gordon et al., 2020) The complex is predicted to nucleate and anchor viral replication complexes on double-membrane vesicles in the cytoplasm (mitochondria)
nsp5	Inhibits interferon I signaling processes by intervening in the NF-κB process and breaking down STAT one transcription factor Functions as 3-chymotrypsin-like protease, cleaves the viral polyprotein (Gordon et al., 2020)
nsp5_c145a	Catalytic dead mutant of nsp5 (Gordon et al., 2020)
nsp6	nsp3–nsp4–nsp6 complex involved in viral replication Limits autophagosome expansion Components of the mitochondrial complex V (the complex regenerates ATP from ADP) copurify with nsp6 (Gordon et al., 2020)
nsp7	Cofactor of nsp12 nsp7–nsp8 complex in part of RNA polymerase (nsp7, 8, 12 – replication complex)Affects electron transport, GPCR signaling, and membrane trafficking (Gordon et al., 2020; Peng et al., 2020b; Romano et al., 2020; Hillen et al., 2020)
nsp8	Cofactor of nsp12 nsp7–nsp8 complex in part of RNA polymerase. Affects the signal recognition particle and mitochondrial ribosome (Gordon et al., 2020; Peng et al., 2020b; Romano et al., 2020; Chi et al., 2003)
nsp9	ssRNA binding protein (can bind both DNA and RNA, but prefers ssRNA) Interacts with the replication complex (nsp7, 8, 12) (Cornillez-Ty et al., 2009)
nsp10	Cofactor of nsp16 and nsp14 (Romano et al., 2020) Essential for nsp16 methyltransferase activity (stimulator of nsp16) Zinc finger protein essential for replication (Gordon et al., 2020; Peng et al., 2020b)
nsp11	Unknown function
nsp12	Functions as an RNA-direct RNA polymerase, the catalytic subunitAffects the spliceosome (Gordon et al., 2020; Peng et al., 2020b; Romano et al., 2020; Hillen et al., 2020)
nsp13	Has helicase and 5’ triphosphatase activity Initiates the first step in viral mRNA capping nsp13,14,16 installs the cap structure onto viral mRNA in the cytoplasm instead of in the nucleus, where the host mRNA is capped (Gordon et al., 2020; Peng et al., 2020b; Romano et al., 2020; Ivanov et al., 2004)
nsp14	In addition to the capping function of the methyltransferase, nsp14 is also an endonuclease (3’–5’ exoribonuclease) that corrects mutations during genome replication (Gordon et al., 2020; Peng et al., 2020b; Romano et al., 2020)
nsp15	Endoribonuclease has uridine-specific endonuclease activity, essential for viral RNA synthesis (Gordon et al., 2020; Romano et al., 2020)
nsp16	May involve complexation with nsp10 and nsp14, for stabilization of homoenzyme, for capping the mRNA (Gordon et al., 2020; Peng et al., 2020b; Romano et al., 2020)
Open reading frame (accessory factors)
orf3a	Packaging into virions Mediates trafficking of spike protein by providing ER/golgi retention signals Induces IL-6b, activates NF-κB, activates the NLRP3 inflammasome (Gordon et al., 2020)
orf3b	Interferon antagonist and involved in pathogenesis (Gordon et al., 2020)
orf6	Type I interferon antagonist, suppresses the induction of interferon, and interferon signaling pathways (Gordon et al., 2020)
orf7a	May be related to viral-induced apoptosis (Gordon et al., 2020)
orf7b	Unknown function
orf8	Recombination hotspot Induces ER stress and activates NLRP3 inflammasomes Low similarity to SAR-CoV (Gordon et al., 2020)
orf9b	Suppresses host antiviral response Targets the mitochondrion-associated adaptor molecules MAVS and limits host cell interferon responses (Gordon et al., 2020)
orf9c	No evidence that this protein is expressed during SARS-CoV-2 infection (Gordon et al., 2020)
orf10	No evidence that this protein is expressed during SARS-CoV-2 infection (Gordon et al., 2020)