RNA-dependent RNA polymerase of coronavirus (RdRp (also known as nsp12))

The **RNA-dependent RNA polymerase (RdRp)**, also referred to as **nonstructural protein 12 (nsp12)**, is a critical enzyme in the coronavirus replication cycle[2][3][6]. It is responsible for the synthesis of new viral RNA genomes and subgenomic RNAs, operating as the core catalytic component of the viral replication-transcription complex. The activity of RdRp is greatly enhanced by its association with essential co-factors nsp7 and nsp8, forming a multimeric complex that confers high processivity and fidelity to RNA synthesis[3][5][9]. Core structural features of the RdRp include a catalytically active palm, fingers, and thumb domain, with highly conserved motifs facilitating nucleotide addition and chain elongation[6][7]. Drugs targeting the RdRp have proven to be among the most effective direct-acting antivirals for COVID-19. Mutations in this polymerase are implicated in drug resistance and can affect the efficacy of treatment. As the central enzyme for viral replication, the coronavirus RNA-dependent RNA polymerase is a validated and essential therapeutic target for combating coronavirus infections[3][10][11].

Other names

nsp12coronavirus polymeraseSARS-CoV nsp12SARS-CoV-2 polymeraseRNA polymeraseviral RNA polymerase

Nucleoside analog inhibitors: Drugs like remdesivir and favipiravir are incorporated into the nascent RNA chain by the RdRp, leading to premature termination or lethal mutagenesis, thus inhibiting viral replication[10][6].