Viral myb oncogene encodes a sequence-specific DNA-binding activity

The retroviral oncogene v-myb and its cellular progenitor c-myb encode nuclear DNA-binding proteins1–5. Myb genes have been identified in a broad range of species, including vertebrates6–9, the fruit fly Drosophila melanogaster10,11 and the plant Zea mays12. The localization of the DNA-binding domain of the v-MYB protein to the highly conserved amino-terminal region11,13 suggests that the MYB/DNA interaction is important for MYB function. We show here that v-MYB specifically recognizes the nucleotide sequence pyAACG/TG. So like other nuclear transforming proteins, v-MYB seems to be a member of the class of sequence-specific DNA-binding factors presumably involved in gene regulation.