Dark Proteome of Newly Emerged SARS-CoV-2 in Comparison with Human and Bat Coronaviruses

Rajanish Giri; Taniya Bhardwaj; Meenakshi Shegane; Bhuvaneshwari R. Gehi; Prateek Kumar; Kundlik Gadhave

thereby promotes the viral entry into the host cells, whereas S2' serves as a viral fusion peptide [52, 53] . Spike binds to the virion M protein through its C-terminal transmembrane region [54] . Belonging to a class I viral fusion protein, S protein binds to specific surface receptor angiotensin-converting enzyme 2 (ACE2) on host cell plasma membrane through its N-terminal receptor-binding domain (RBD) and mediates viral entry into host cells [55] . The S protein consists of an N-terminal signal peptide, a long extracellular domain, a singlepass transmembrane domain, and a short intracellular domain [56] . A 3.60 Å resolution structure (PDB ID: 6ACC) of S protein from Human SARS complexed with its host binding partner ACE2 has been obtained by cryo-electron microscopy (cryo-EM The biophysical analysis reported in previous study has also revealed that the S protein from SARS-CoV-2 has a higher binding affinity to ACE2 than S protein from Human SARS [58] . The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.13.990598 doi: bioRxiv preprint which has been calculated by averaging the disorder scores from all six predictors is represented by a short-dot line (sky-blue line) in the graph. The light sky-blue shadow region signifies the mean error distribution. The residues missing in the PDB structure or the residues for which PDB structure is unavailable are represented by the grey-coloured area in the corresponding graphs. (E) Aligned disorder profiles generated for spike glycoprotein from SARS-CoV-2 (black line), Human SARS (red line), and Bat CoV (green line) based on the outputs of the PONDR ® VSL2.