Figure 2.

The topological structure of ScCD8αα extracellular region. (A) Cartoonstructure of the ScCD8αα homodimer, CD8α monomers are colored blue and orange. The β-strands are labelled. Disulfide bonds are shown as sticks and colored lime green. (B) The monomer structure of the ScCD8α extracellular region. (C) Comparison of ScCD8α extracellular region to that of other species. All the structures are shown in cartoon representation. The ScCD8α is colored blue, grass carp CD8α is lime green, chicken CD8α is yellow, bovine CD8α is cyan, human CD8α is pink, mouse CD8α is orange, monkey CD8α is limon, and swine CD8α is light magenta. Helix A of ScCD8α, swine CD8α, and grass carp CD8α are labeled. Helix C’ of ScCD8α is labeled in the righthand panel. PDB accession numbers for each structure are as follows; human CD8αα 1CD8, chicken CD8αα 5EB9, swine CD8αα 5EDX, grass carp CD8αα 5Z11, monkey CD8αα 2Q3A, mouse CD8αα 2ARJ and bovine CD8αα 5EBG. (D-G) Two-dimensional topology diagrams of vertebrate CD8αs. The strands form a sandwich of 2 sheets in the catshark, grass carp, chicken, and human, which are colored blue, lime green, orange, and pink respectively, β-strands are labeled.