Although the genome of the SARS-CoV-2 virus has been available since January, how the virus transcribes and uses its genome was not known. As an RNA virus, SARS-CoV-2 produces many smaller RNAs called subgenomic RNAs once it enters the host cell. These subgenomic RNAs might be good targets for stopping the progression of COVID-19, the disease called by SARS-CoV-2.
In the present study, Kim and her team have successfully combined two different RNA sequencing methods to dissect the architecture of the SARS-CoV-2 genome. The researchers not only confirmed the predicted the subgenomic RNAs that are translated into viral proteins but also revealed exactly where the genes are located on the genomic RNA.
“Apart from detailing the structure of SARS-CoV-2, we also discovered numerous new RNAs and multiple unknown chemical modification on the viral RNAs. Our work provides a high-resolution map of SARS-CoV-2. This map will help understand how the virus replicates and how it escapes the human defense system,” said Kim, who is the director of the IBS Center for RNA Research.
In addition to confirming that only nine out of the ten previously known subgenomic RNAs exist, the researchers also found that there are dozens of unknown subgenomic RNAs, owing to RNA fusion and deletion events.