SARS-CoV-2

Coronavirus SARS-CoV-2, which began to spread in China from Wuhan in December 2019, is the causative agent of COVID19, which is associated with severe acute respiratory syndrome (SARS). Three months after its emergence, the virus was able to infect 350,000 people worldwide, of which 15,000 fatally. Until the outbreak of the SARS epidemic in 2002 and 2003 in China, in Guangdong province, coronaviruses were considered to cause only mild respiratory and intestinal infections. Ten years after SARS-CoV, another highly pathogenic coronavirus, MERS-CoV (*Middle East Respiratory Syndrome*) has appeared in the Middle East. The natural reservoir of SARS-CoV, MERS-CoV and SARS-CoV-2 are bats from which they are transmitted to the human population via an intermediate host (civets, camels and possibly pangolins).



The virus belongs to the beta-coronaviruses of the family Coronaviridae of the order Nidovirales. The cellular receptor by which SARS-CoV-2 enters the cell is a protein called angiotensin convertase (ACE-2). ACE-2 is an important molecule of our body found on the surface of the lung, heart, kidney and intestine cells to regulate blood pressure and heart rate. The coronavirus is attached to ACE-2 by the spike protein. Coronaviruses of bats, civets or pangolins use the same molecule to enter the cell. SARS-CoV-2 is encoded by a positive single stranded RNA of approximately 30,000 nucleotides. The first molecular biological event of coronaviruses after cell entry and binding to the ribosome is the translation of proteins forming the viral particle (spike of envelope glycoprotein (S), envelope (E), membrane (M) and nucleocapsid protein (N)) and proteins necessary for virus multiplication (polymerase (Pol) and protease (Pr)), which do not enter the virus particle.