Kheryl Lucie
Coronaviruses can infect a wide range of animals. Two highly contagious and pathogenic coronavirus members have spread in different countries over the last two decades. SARS (severe acute respiratory syndrome coronavirus) first appeared in East Asia in 2002, and Middle East respiratory syndrome coronavirus (MERS) first appeared in the Middle East in 2012. Then, in 2019, a brand-new member of the coronavirus family, acute respiratory syndrome coronavirus 2 (SARS-CoV-2), caused a disease that was later dubbed coronavirus disease 2019 (COVID-19). The COVID-19 virus was discovered in Wuhan, China, and it fueled a global pandemic that infected billions of people. SARS-CoV-2 is a novel -coronavirus that shares 79% and 50% of its genome sequence with SARS-CoV and MERS-CoV24, respectively. SARS-CoV-2 contains six functional open reading frames (ORFs) arranged in 5′-3′ order: Replicase (ORF1a/ORF1b), spike protein (S), envelope protein, membrane protein (M), and nucleocapsid (N). There are also scattered genes encoding accessory proteins among the structural genes, such as ORFs 3, 6, 7a, 7b, 8, and 10. SARS-fulllength CoV-2's 29,903 nucleotides encode 27 viral proteins.
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