The CoV envelope (E) protein is the smallest among the four structural proteins involved in several aspects of the virus life cycle, such as assembly, budding, envelope formation, and pathogenesis [7]. However, the molecular mechanism involving E-protein in pathogenesis is not yet clearly understood. Notably, this protein interacts with other structural proteins such as membrane(M) and other accessory proteins viz. ORF3a, ORF7a and host cell proteins [8]. Envelope protein of SARS-CoV2 is 76 amino acids long and possesses three important domains viz. (N)-terminus, transmembrane domain (TMD) and (C)-terminus (Fig. 1 ). The (C)-terminal domain of envelope protein in SARS-CoV2 binds to human PALS1, a tight junction-associated protein, which is essential for the establishment and maintenance of epithelial polarity in mammals [9,10].
Fig. 1 Amino acid sequence and domains of the envelope protein of SARS-CoV2 [7].
Red and blue colors are representing hydrophobic and hydrophilic amino acid, respectively. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)