title: Comparison of the entire genomes of bovine leukemia virus and human T-cell leukemia virus and characterization of their unidentified open reading frames.
abstract: We have compared the sequence of the entire genomes of bovine leukemia virus (BLV) and human T-cell leukemia virus type I (HTLV-I). Both the gag and pol genes show overall strong homologies indicating the close evolutionary relationship of the two retroviruses. However, a surface glycoprotein portion of the env gene shows no appreciable homology, which probably reflects a difference in their host ranges. The 3' end portion of the BLV genome (designated as pXBL) contains an unidentified long open reading frame that has a typical protein-coding property. The potential product of this open reading frame may be a glycoprotein of approximately 40 000 daltons. We note that its amino acid sequence shows low but appreciable homology, especially in its N-terminal quarter, to that of the HTLV-I counterpart (pX product), and we thus suggest that BLV pXBL and HTLV-I pX have diverged from a common ancestral gene. It is tentatively concluded that both the putative pXBL and pX products are respectively produced from a spliced mRNA.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D017977:Deltaretrovirus / Q000235:genetics*; D005796:Genes; D005814:Genes, Viral; D006023:Glycoproteins / Q000235:genetics; D001909:Leukemia Virus, Bovine / Q000235:genetics*; D012326:RNA Splicing; D012190:Retroviridae / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics
chemical_list: D006023:Glycoproteins; D014764:Viral Proteins