Fig. (1) (A). Schematic representation of the structural organization of rotavirus NSP4. H1, H2 and H3, N-terminal hydrophobic domains; ECM, Extra Cellular Matrix; ISVD, Interspecies variable domain; DLP, Double-layered particle, (B). Amino acid sequence alignment of the NSP4ΔN72 region from different rotavirus strains used in this study. E158K and K158E represent the mutant NSP4 proteins generated by site-directed mutagenesis using PCR from the symptomatic (N136) and asymptomatic (2KD/851) Vellore strains, respectively.