Some notes on Virus
There are 219 virus species that are known to be able to infect humans. The first of these to be discovered was yellow fever virus in 1901, and three to four new species are still being found every year. Following on from the discovery of tobacco mosaic virus in 1892 and foot-and-mouth disease virus in 1898, the first ‘filterable agent’ to be discovered in humans was yellow fever virus in 1901.
SARS-COV-2 is a single stranded RNA virus, and it has 82% (need reference) sequence similarity with SARS-COV that lead to the outbreak in 2003. The RNA is approximtately 30kb in length–the largest RNA viruses, with 5’-cap structure and 3’-polyA tail. Amongh the structural elements of SARS-COV, there are the spike glycoproteins composed of two subunits. The spike proteins are the one that bind to humean ACE-2 binding receptors and initiate the entry to the cells. The structures of spike proteins can be found at PDB databank. According to my limited knowledge, there are two different conformtions, 6VXX for closed spike and 6VYB for open spike. There is also 2AJF that shows the binding of S1 protein with huamn ACE2 receptor.