What is SARS virus?
The SARS virus is spherical and has a diameter of about 100 nm. It is an enveloped single-stranded positive-strand RNA virus and is the largest known RNA virus. Like other coronaviruses, the SARS virus envelope also has a wide array of spike proteins shaped like a corona. The S protein of coronavirus is the main antigen component of the virus and the site where the virus binds to the receptor. It is also related to cell fusion caused by the virus. M protein is a membrane glycoprotein, which is involved in virus budding and envelope formation. N protein is a phosphoprotein with unclear function and may be involved in the synthesis of viral nucleic acid. HE protein is only found in a few strains, which may be related to the hemagglutination characteristics of some strains. Since the research on SARS virus has just started, the similarities and functions of spike protein and other coronaviruses are yet to be studied.