Coronaviruses are zoonotic pathogens that are well known to evolve, infiltrate and infect many animal species. The recent surfacing of the novel coronavirus (2019-nCoV) in Hubei Province, China has been linked to the Huanan Seafood Wholesale Market in Wuhan and has now infected over 70,000 people with over 1,800 deaths — spreading globally via travelers and breaching the boundaries of 29 countries. The virus is considered to behave very similarly to the Sudden Acute Respiratory Syndrome (SARS)-coronavirus that caused a deadly outbreak in 2002-2003; however, 2019-nCoV is more widely transmissible (although less deadly).
The study sought to model structural aspects of the 2019-nCoV viral binding proteins (spike glycoproteins), which control disease development. While highly SARS-like in overall structure and in the receptor binding domain, a notable difference with SARS-CoV and other SARS-like viruses originating in bats was found in one of the spike protein activation sites. The 2019-nCoV spike contained an extended activation loop that is predicted to control virus entry into host cells. This feature was more in common with a different coronavirus (MERS-CoV), which is currently causing an ongoing outbreak in the Middle East. 2019-nCOV’s extended activation loop likely controls the sequence of triggers needed to allow the viral spike protein to gain access to its target cells and may regulate virus stability.
This modeling study provides data for experimental follow-up and may explain the higher transmission rate of 2019-nCoV compared to SARS-CoV.Friday Letter Submission, Publish on February 28