Fig. 2

Identification of macrodomain-specific substitutions in polyprotein pp1ab of SARS-CoV-2. (a). Schematic representation of genome of SARS-CoV-2 with numbering above the block refers to the nucleotide positions. Structural proteins including spike (S), envelope (E), membrane (M), and nucleocapsid (N) proteins, as well as the nonstructural proteins (nsps) translated from ORF1ab and the accessory proteins, are represented. (b). Schematic representation of 7096-amino acid long polyprotein pp1ab with its 15 sub-proteins (nsp1– nsp10) and (nsp12– nsp16). The positions of macrodomains (Macs: Mac-1, Mac-2, and Mac-3) within Nsp3 are highlighted as a red box demarcated by dotted lines. Numbering above the schematic representation in panel b refers to amino acid positions.(c). Comparative Sequence analysis of pp1ab polyprotein of SARS-CoV-2 strains isolated from Pakistan with reference Wuhan strain of SARS-CoV-2 (YP_009725299.1), and closely related Bat-CoVs, i.e., Bat-RaTG13 (QHR63299.1), and Bat-SL-CoV (AVP78030.1). Red, green, and blue colors in the alignment represent the Mac-1, Mac-2, and Mac-3 substitutions, respectively. Panel c, position 1426, the blue asterisk represents a deletion of amino acid.(d). The graph shows the frequency of macrodomain-specific amino acid substitutions in the dataset of 203 samples from Pakistan from first wave of pandemic (March 01, 2020, to June 30, 2020). Y-axis represents the frequency of substitutions in Pakistani isolates, whereas the X-axis shows the amino acid substitution position