Scientists at the University of Cambridge in the UK have uncovered the key genetic changes that led to the emergence of the SARS-CoV-2 coronavirus, which is pathogenic for humans. Details on the origin of the dangerous strain are given in an article published in the journal PLOS Biology. This was announced in a press release on Phys.org.
The genetic adaptations identified were similar to those produced by the SARS-CoV virus that caused the SARS outbreak in 2003. They allowed the virus to pass from bats to humans. Scientists have suggested that there may be a common mechanism that makes this group of viruses prone to mutations, making it possible to move to new hosts.
Scientists analyzed the related SARS-CoV-2 coronavirus RaTG13, the genome of which is 96 percent similar to the genome of the causative agent COVID-19. Important genetic differences involve the S-protein (spike protein), which plays a key role in the infection of human cells with the coronavirus. It turned out that in RaTG13, the S-protein cannot effectively bind to human cellular receptors. At the same time, if certain fragments of the SARS-CoV-2 S protein are inserted into the RaTG13 spike protein, the binding efficiency will increase.
SARS-CoV-2 does not bind to the cell receptors of bats, which indicates the existence of an intermediate host.