MERS or Middle East Respiratory Syndrome is a virus outbreak that occurred in 2012 in Saudi Arabia. Because of its origin from Middle East and the fact that it came from bats and somehow transferred to camels and then from camels, it found its way to the humans, it was named MERS. MERS virus is actually one of the many viruses from coronavirus family and the most recent virus of this family is COVID 19 that originated in Wuhan, China and within 4 months, it reached more than 200 countries around the world and infected more than 3 million people. While common viruses can only cause flu and cold, this MERS virus was and still is known for causing pneumonia and if it went untreated, patient was under critical threat of unconsciousness and death. If we talk about numbers, this virus doesn’t seem very dangerous as in last 8 years, it has only infected less than 600 people across different countries and continents but you should understand that the fatality rate is more than 30% which is greater than most of the common diseases and virus attacks.
Structure of MERS Coronavirus:
When it comes to structure of MERS coronavirus, it’s almost similar to that of SARS and COVID 19. In fact, SARS, MERS and COVID 19 are the members of same coronavirus family but they lie in different sections or groups within the family due to small differences in their features and characteristics. Just like any other coronavirus, MERS have Spike glycoprotein, Membrane glycoprotein, Nucleocapsid glycoprotein, envelope glycoprotein and genome RNA. The key difference between MERS and SARS is the structure of the spike and data in the genome RNA.
The S glycoprotein on the outside of the shell of the MERS virus is responsible for attaching it to human cells while the M glycoprotein and E glycoprotein aid the virus to replicate itself within the first few hours of latching onto a human cell. While we discuss the structure of MERS virus, keep in mind that this virus belongs to the coronavirus family which is notoriously famous for having longest RNA strands that can go up to 125NM in some cases. MERS genome is consisted on five terminal structures along with poly tails. When the MERS virus enters human body and it reaches the lungs, the spikes on the outside shell of the virus are responsible for attaching it to a living cell and this is done by attaching with the host cell receptor DPP4 via RBD.
As soon the virus attaches itself on the cell surface, M and E glycoproteins start their work by replicating the virus multiple times and this is done so quickly that within few hours, there are can be millions of replicated viruses in the human body. On the other hand, N glycoprotein is responsible for RNA synthesis. One important thing to notice is that there are more than 50 types of coronaviruses that circulate among humans and animals but not each of them has the ability to attack a human being. This was true before the discovery or identification of MERS in humans and this lead to the research of how this virus actually changed the form and shape of its spike glycoproteins to easily attach to the human blood cells. This way done when the virus was transferred from the first host to the second host and finally to the humans.