Figure 3

Arrangements of the helices and loops depending on the Ω and λ dihedral angles. The central figure presents the front view of three consecutive helices in the membrane proteins. H_(n) represents the helices and L_(n) represents loops. (a) Front view of the arrangement of two adjacent helices, H_i and H_i+1 when Ω_i = 0°, (b) Front view of the arrangement of two adjacent helices, H_i and H_i+1 when Ω_i =  ± 180°, (c) Top view of the arrangement of two adjacent loops, L_i and L_i+1, and three adjacent helices, H_i, H_i+1 and H_i+1, when λ_i = 0°, and (d) Top view of the arrangement of two adjacent loops, L_i and L_i+1, and three adjacent helices, H_i, H_i+1 and H_i+1, when λ_i = ±180°. These figures show the possible scenario depending on the dihedral angles rather than a real arrangement observed in TM proteins.