Molecular Dynamics of SARS-CoV-2 RNA Synthesis and Regulation

The replication and transcription of the SARS-CoV-2 genome are governed by a finely tuned molecular choreography in which viral non-structural proteins assemble into a dynamic replicase–transcriptase complex (RTC). Central to this process is the RNA-dependent RNA polymerase (RdRp), supported by accessory cofactors that enhance processivity, regulate subgenomic RNA synthesis and coordinate proofreading. A dedicated exoribonuclease activity embedded within nsp14 excises misincorporated nucleotides, preserving genome integrity across the unusually large coronavirus genome. Concomitant capping and cap methylation of nascent RNAs—mediated by sequential N7- and 2′-O-methyltransferases in complex with nsp10—ensures mimicry of host mRNAs, facilitating efficient translation and immune evasion. High-resolution structures have revealed conformational rearrangements at key interfaces, while biochemical studies have begun to map regulatory switches that balance replication speed, fidelity and the timing of subgenomic transcription. Understanding these molecular dynamics is crucial for identifying allosteric sites for antiviral intervention and for predicting the impact of emerging mutations on viral fitness and pathogenicity.

Research from Nature Portfolio

Recent studies have delineated how intrinsically disordered regions of human proteins engage folded domains of viral non-structural proteins, identifying low-affinity peptide interactions that perturb host pathways and, in some cases, directly inhibit viral replication. Structural analyses of the full replication–transcription complex have elucidated inter-subunit interfaces and allosteric networks that regulate RNA synthesis, proofreading and cap formation, revealing potential druggable pockets. In-depth characterisation of the nsp10–nsp16 methyltransferase complex bound to a pan-MTase inhibitor has demonstrated high conservation of the active site among betacoronaviruses, guiding the rational design of broad-spectrum cap-methylation inhibitors.

Molecular Dynamics of SARS-CoV-2 RNA Synthesis and Regulation publication trend

The graph below shows the total number of articles in molecular dynamics of sars-cov-2 rna synthesis and regulation across all publications each year (not limited to Nature Index journals).

Technical terms

RNA-dependent RNA polymerase (RdRp): The viral enzyme that synthesises RNA from an RNA template, driving genome replication and transcription of subgenomic RNAs.

Exoribonuclease (ExoN): A 3′–5′ proofreading activity within nsp14 that removes erroneous nucleotides to maintain high-fidelity replication of the large coronavirus genome.

2′-O-methyltransferase (2′-O-MTase): The enzyme function, usually within nsp16 in complex with nsp10, that methylates the ribose 2′-hydroxyl group of the RNA cap structure to mimic host mRNA.

Replicase–transcriptase complex (RTC): The multi-protein assembly comprising viral non-structural proteins and essential cofactors that orchestrates synthesis, proofreading and processing of viral RNA.

References

1. Natural evidence of coronaviral 2′-O-methyltransferase activity affecting viral pathogenesis via improved substrate RNA binding. Signal Transduction and Targeted Therapy (2024).
2. Identification of motif-based interactions between SARS-CoV-2 protein domains and human peptide ligands pinpoint antiviral targets. Nature Communications (2023).
3. Nsp14 of SARS-CoV-2 inhibits mRNA processing and nuclear export by targeting the nuclear cap-binding complex. Nucleic Acids Research (2023).
4. A Structural View of SARS-CoV-2 RNA Replication Machinery: RNA Synthesis, Proofreading and Final Capping. Cells (2020).
5. Structures and functions of coronavirus replication–transcription complexes and their relevance for SARS-CoV-2 drug design. Nature Reviews Molecular Cell Biology (2021).
6. Structural analysis of the SARS-CoV-2 methyltransferase complex involved in RNA cap creation bound to sinefungin. Nature Communications (2020).