Plot of predicted structural disorder tendency of the consensus envelope protein.

Disorder tendency for each amino acid is predicted by four prediction methods (0 represents complete order; 1 represents complete disorder; scores over 0.4 represent intrinsically disordered). Disorder tendency scores are plotted for consensus R5, R5X4 and X4 envelope sequence for DISOPRED3 (A), IUPred (B), PONDR VL-XT (C) and PONDR VSL2 (D), respectively. (E) The consensus protein sequences of R5, R5X4 and X4 are aligned to HXB2 envelope sequence (gp120 and gp41) for indicating the structure locations of the disordered residues (adapted from Jiang et al. 2015 [61]). Gp120 and gp41 protein domains are numbered and color-coded for visualisation. Note that here the length of the Env sequence is longer than the normal one because gaps are introduced in the sequence alignment and dashed lines are used for linking sites with missing prediction scores in the gaps.