Nucleotide sequence and organization of the transforming region and large terminal redundancies (LTR) of avian myeloblastosis virus (AMV)

Abstract

Avian myeloblastosis virus (AMV) is a replication-defective acute leukemia virus, requiring a helper virus to provide the viral proteins essential for synthesis of new infectious virus. The genome of the AMV has undergone a sequence substitution in which a portion of the region normally coding for the "env" protein has been replaced by chicken cellular sequences. These latter sequences are essential for the transforming activity of the virus. We have determined the complete nucleotide sequence of this region. Examination of the AMV oncogenic sequence revealed an open reading frame starting with the initiation codon ATG within the acquired cellular sequences and terminating with the triplet TAG at a point 33 nucleotides into helper viral sequences to the right of helper-viral-cellular junction. The stretch of 795 nucleotides would code for a protein of 265 amino acids with a molecular weight of 30,000 daltons. The eleven amino acids at the carboxy terminus of such a protein would be derived from the env gene of helper virus.