Crystal structure of COVID-19 main protease in complex with an inhibitor N3 (PDB ID: 6LU7) , SARS-Coronavirus NSP12 bound to NSP7 and NSP8 co-factors(6NUR) and Pre-fusion 2019-nCoV spike glycoprotein with a single receptor-binding domain (6VSB) retrieved from the Protein Data Bank available at . Additionally, computationally predicted 24 modelled structures based on protein sequences translated from the complete genome of Severe acute respiratory syndrome coronavirus 2 isolate Wuhan-Hu1 (Genbank Accession: MN908947.3) available on I-TASSAR online server also included in the present study (Table ) . Total 27 receptors threedimensional structures were subjected addition of Hydrogen for pH 7.0 and Gasteiger charges were using Open Babel . The resulting structures converted to PDBQT format using python script -prepare_receptor.py‖ from AutoDock Tools .