Scientists at the University of Cambridge in the United Kingdom have uncovered the key genetic changes that led to the human pathogenic coronavirus SARS-CoV-2. Details about the origin of the dangerous strain are given in an article published in the journal PLOS Biology.
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 switch from bats to humans. Scientists have suggested that there may be a common mechanism that makes this group of viruses prone to mutations that make the transition to new hosts possible.
Scientists analyzed the related SARS-CoV-2 coronavirus RaTG13, whose genome is 96 percent similar to that of the pathogen COVID-19. Important genetic differences affect the S-protein (spike protein), which plays a key role in infecting human cells with the coronavirus. It turned out that in RaTG13, the S-protein cannot efficiently bind to human cell receptors. At the same time, if certain fragments of SARS-CoV-2 S-protein were inserted into the RaTG13 “spike” protein, the binding efficiency would increase.+
SARS-CoV-2 does not bind to bat cell receptors, indicating the existence of an intermediate host.