FIG. 5.

Schematic representation of the HTLV-1 Env glycoprotein gp21 and the amino acid sequence of the gp21 peptide 400-429. The fusion peptide domain (FP), extracellular domain (EC), transmembrane domain (TM), and intracellular domain (IC) are indicated. The positions of the leucine zipper-like region (LZR) (amino acids 340 to 392) and the immunodominant region (IDR) (amino acids 377 to 402) are also indicated. The N-glycosylation site of HTLV-1 Env gp21 (at position 404) (closed circle) is underlined.