Figure 1.

Expression of the x-II ORF of HTLV-1. (a) HTLV-1 genome, ORFs, transcripts, and protein products are shown. The exon boundaries are indicated below each transcript, with nucleotide numbering starting at the first nucleotide in the R region of the LTR. (b) Protein sequences of p30^II (expressed from mRNA 1-2-B; in grey letters) and p13^II (expressed from mRNA 1-C; in black letters) coded by HTLV-1 molecular clone ATK are shown. The p13^II sequence spans nucleotides 6936–7197 and corresponds to the C-terminal 87 amino acids of p30^II. The bipartite NLS of p30^II and the MTS of p13^II are underlined. (c) Differences in the p13^II amino-acid sequence of the indicated viruses compared to ATK p13^II (see b) are shown. ATK and ATL-YS are proviruses cloned directly from peripheral blood lymphocytes of Japanese ATLL patients.³,⁴ CS-HTLV is a full-length, infectious provirus derived from a North American ATLL patient.⁵ HS-35 is a molecular clone obtained from an infected patient of Caribbean origin.⁶ IMEL5 is an HTLV-1 isolate from a healthy Melanesian Solomon Islander.⁷ Isolates HH, TE, TG and TD are from healthy carriers (HH) and HAM/TSP patients;⁸,⁹ changes are based on published analyses of the portion of exon 3 (the second Tax/Rex exon) overlapping with exon C