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

The copyright holder for this preprint (which was not peer-reviewed) is the .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 published structure has the highly polarized distribution of charges, with positively charged residues on the one side of the tent and negatively charged on the other [121] . Based on the sequence availability of accession ID NC_045512.2, the translated protein sequence of ORF9b is not reported for the SARS-CoV-2 as of yet. However, based on the report by Wu and colleagues [45] , the sequences of the SARS-CoV-2 are already annotated. Therefore, we took the corresponding amino acid sequences from that study and conducted the intrinsic disorder analysis. According to the MSA, results shown in Figure 14E , ORF9b protein from SARS-CoV-2 shares 73.2% identity with Human SARS and 74.23% identity with Bat CoV. Our IDP analysis ( Table 1) shows that ORF9b from Human SARS is a moderately unstructured protein with a mean PPID estimated to 26.53%. As depicted in Figure 14A , 14B, and 14C, disorder mainly lies near the N-terminal end 1-10 residues and 28-40 residues near the central region with a well-ordered inner core of Human SARS ORF9b protein. The x-ray crystal structure of ORF9b has a missing electron density of the first 8 residues and 26-37 residues near the central region. This indicates that the corresponding regions are disordered, which are difficult to crystallize due to their highly dynamic structural organization. SARS-CoV-2 ORF9b protein with a mean PPID of 10.31% has an N-terminal (1-10 residues) predicted disordered segment. ORF9b of Bat CoV is shown to have an author/funder. All rights reserved. No reuse allowed without permission.