The ectodomain of a TLR3 subunit.⁵¹  “Worms” rendering with yellow arrows indicating beta sheet and green coil indicating alpha helix, imaged with the program CN3D. From NCBI protein database, PDB 1ZIW. Amino terminal (N) and carboxy terminal (c) ends of the structure are indicated. Loops outside the solenoid (arrow) may give flexibility to the protein. Carbohydrate residues (ball and stick) may influence association between subunits and/or binding of ligand.