Human T-Cell Leukemia-Virus Type-Ii - Primary Structure-Analysis Of The Major Internal Protein, P24 And The Nucleic-Acid Binding-Protein, P15

The 24,000-molecular-weight major internal protein (p24) and the 15,000-molecular-weight nucleic acid binding protein (p15) of human T-cell leukemia virus type II (HTLV-II) were subjected to amino acid composition and amino-terminal amino acid sequence analysis. A comparison of amino acid composition of p24 and p15 of HTLV-II with those of the analogous proteins of HTLV-I revealed that these two proteins share overall similarity. Further, alignment of the amino-terminal amino acid sequence for the first 27 residues of p24 and 34 residues of p15 from HTLV-II showed extensive sequence homology with analogous proteins of HTLV-I. These data suggest that although disease associated with HTLV-I is malignant T-cell leukemia and that associated with HTLV-II is a relatively benign variant of hairy-cell leukemia, HTLV-I and HTLV-II are closely related to each other, at least in their gag -gene-encoded sequences.