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

intrinsically disordered proteins (IDPs) and intrinsically disordered protein regions (IDPRs)), in order to better understand an interplay between the ordered and disordered components of the proteome. In classical structure-function-paradigm, it is believed that a unique, stable, and well-defined 3-dimensional structure is a prerequisite for a protein to accomplish its unique biological function. Although this notion dominated scientific minds for over the hundred years, eventually an idea of the presence of functional intrinsic disorder in proteins came to the attention of the structural biologists. According to this "heretic" viewpoint, a noticeable amount of biologically active proteins (of protein regions) fail to fold into the well-defined structures and instead remain disordered, existing as highly dynamic ensembles of rapidly interconverting conformations under the physiological conditions. These proteins and protein regions are known now as intrinsically disordered proteins (IDPs) and intrinsically disordered protein regions (IDPRs), respectively. The propensity of being functional intrinsically disordered proteins (similar to the propensity of forming unique biologically active structures of ordered proteins) is determined by the amino acid sequences [11] [12] [13] . IDPs exhibit their biological functions in numerous biological processes commonly associated with cellular signalling, gene regulation, and control by interacting with their physiological partners [14] [15] [16] [17] [18] . These functions of IDPs and IDPs are regulated by their protein-protein, protein-RNA, protein-DNA interactions [19, 20] . Molecular recognition features (MoRFs) are the regions in IDPs implicated in regulation of IDPs function by protein-protein interactions and serve as the primary stage in molecular recognition. and DISOPRED3 [42] . The protein residues with ANCHOR, MoRFPred, and DISOPRED3 score above the threshold value of 0.5 and MoRFchibi_web score above the threshold value of 0.725 are considered MoRF regions.