Abstract
BACKGROUND: SARS-CoV-2 which causes COVID-19 disease has started a pandemic episode all over the world infecting millions of people and has created medical and economic crisis. From December 2019, cases originated from Wuhan city and started spreading at an alarming rate and has claimed millions of lives till now. Scientific studies suggested that this virus showed genomic similarity of about 90% with SARS-CoV and is found to be more contagious as compared to SARS-CoV and MERS-CoV. Since the pandemic, virus has undergone constant mutation and few strains have raised public concern like Delta and Omicron variants of SARS-CoV-2. OBJECTIVE: This review focuses on the structural features of SARS-CoV-2 proteins and host proteins as well as their mechanism of action. We have also elucidated the repurposed drugs that have shown potency to inhibit these protein targets in combating COVID-19. Moreover, the article discusses the vaccines approved so far and those under clinical trials for their efficacy against COVID-19. CONCLUSION: Using cryo-electron microscopy or X-ray diffraction, hundreds of crystallographic data of SARS-CoV-2 proteins have been published including structural and non-structural proteins. These proteins have a significant role at different aspects in the viral machinery and presented themselves as potential target for drug designing and therapeutic interventions. Also, there are few host cell proteins which helps in SARS-CoV-2 entry and proteolytic cleavage required for viral infection.