S. no | Proteins | Functions | Refs |
---|---|---|---|
1. | nsp1 | Interferes with the mRNA binding and suppresses hosts’ immune functions Anchors the replication complex to cellular membranes Degrades host’s mRNA by interacting with the human 40S ribosomal subunit | |
2. | nsp2 | Harbours mutations that make it more contagious Might play a role in modulation of host cell survival; also known as p65 homolog | |
3. | nsp3 | Papain-like protease 2 (PL2pro) involved in proteolytic cleavage | [135] |
4. | nsp4 | Responsible for the formation of the double membrane vesicle during replication Anchors the viral replication-transcription complex to the membranes of endoplasmic reticulum | |
5. | nsp5 | Proteases (3CLpro, Mpro) involved in polypeptide cleaving | [138] |
6. | nsp6 | Prevents the expansion of autophagosome, Help in formation of double membrane vesicle; suppresses IFN-I signaling | |
7. | nsp7 | Forms a hexadecamer with nsp8 and acts as a primase in viral replication | [141] |
8. | nsp8 | Acts as a primase with nsp7 | |
9. | nsp9 | Acts as ssRNA binding protein | |
10. | nsp10 | Plays role in the methylation of viral mRNA cap. Stimulates the nsp14 3′-5′ exoribonuclease and 2′-O-methyltransferase (NSP16) activities | [144] |
11 | nsp11 | Unknown | |
12 | nsp12 | Catalytic subunit of the RNA-dependent RNA polymerase; Catalyses the synthesis of viral RNA, using nsp7 and nsp8 as cofactors | |
13. | nsp13 | Helicase and NTPase activity: hydrolyze the NTPs and unwind the duplex RNA and DNA with a 5′ single-stranded tail in a 5′ to 3′ direction A potent interferon antagonist | |
14. | nsp14 | Guanine-N7 methyltransferase, a multienzyme complex Acts on both sides ssRNA and dsRNA in a 3′-> 5′ direction A potent interferon antagonist It plays role in genome replication, sub-genomic RNA synthesis and recombination | |
15. | nsp15 | It is a nidoviral RNA uridylate‐specific endoribonuclease (NendoU); plays role in viral replication and transcription A potent interferon antagonist | |
16. | nsp16 | Acts as 2′-O-methyltransferase that mediates mRNA cap 2′-O-ribose methylation to the 5′-cap structure of viral mRNAs |