SARS-CoV-2 replication and polyprotein processing complex (SARS-CoV-2 replication complex)

The SARS-CoV-2 replication and polyprotein processing complex represents the core enzymatic machinery required for the propagation of the virus within a host. This process involves two primary stages: the cleavage of large viral polyproteins (pp1a and pp1ab) into individual functional non-structural proteins (NSPs) and the subsequent replication of the viral RNA genome (UniProt: P0DTD1). Protein maturation is primarily governed by the Main Protease (Mpro or 3CLpro) and the Papain-like Protease (PLpro), which are essential for releasing the enzymes necessary for the viral life cycle (PubMed: 32275855). RNA replication is executed by the RNA-dependent RNA polymerase (RdRp) complex, centered on the NSP12 protein, which catalyzes the synthesis of new viral RNA strands (PubMed: 32330252). Because these enzymes are highly conserved among coronaviruses and lack human homologs, they are ideal targets for antiviral therapy. Drugs such as Nirmatrelvir target the Mpro to block protein maturation, while Remdesivir and Molnupiravir target the RdRp to disrupt RNA synthesis, effectively halting viral replication and reducing the severity of COVID-19 (NIH: COVID-19 Treatment Guidelines).

Other names

SARS-CoV-2 RNA-dependent RNA polymerase complexSARS-CoV-2 Main Protease3C-like proteaseMpro3CLproPapain-like proteasePLproRdRpNSP12-NSP7-NSP8 complexSARS-CoV-2 non-structural proteins

Inhibition of the RNA-dependent RNA polymerase (RdRp) to terminate RNA chain elongation or induce lethal mutagenesis; inhibition of the 3C-like protease (Mpro) or Papain-like protease (PLpro) to prevent the cleavage of viral polyproteins (pp1a and pp1ab) into functional non-structural proteins required for viral assembly and replication.