Viperin domain representation, predicted model, structural property and hydrophobic environment of Viperin surrounding three cysteines.

(a) The domain representation of Viperin containing N-terminal amphipathic helix (residues 1–42) shown in blue color rectangular box; a middle domain that contains a conserved S-Adenosyl-L-Methionine (SAM) domain shown in violet color rectangular box and a Leucine Zipper domain; and a highly conserved C terminal domain shown in red color rectangular box. (b) The modeled structure of Viperin. Three cysteines at the positions 83, 87, 90 (shown as sticks of magenta color) are present at the bottom of the central pocket. This pocket has been surrounded by parallel beta strands forming the first layer (shown in yellow color). A layer of alpha helices (shown in red color) is also found just above the beta sheets. All these alpha helices and beta sheets are arranged in alternating order in the primary sequence separated by coils and loops shown in green color. (c) The fluctuations of the radius of gyration (R_g) of a 20 ns simulation run of WT Viperin. (d) The fluctuations of the radius of gyration (R_g) of a 20 ns simulation run of triple cysteine mutant of Viperin. (e) Hydrophobic environment of Viperin around three cysteine molecules. Cysteine residues at the positions 83, 87, 90 are shown as sticks of blue color and hydrophobic patches are shown as spheres of red color. All other regions of the protein are shown as black. Cys83 and Cys87 are surrounded by most of the hydrophobic groups whereas Cys90 is placed towards the surface of the protein.