NUCLEOTIDE-SEQUENCE OF THE OVINE P53 TUMOR-SUPPRESSOR CDNA AND ITS GENOMIC ORGANIZATION

A 2155 bp cDNA clone corresponding to the ovine p53 tumor suppressor gene has been isolated from a cDNA library made from the BLV-transformed YR2 cell line RNA. After the sequencing analysis, it appeared that this clone contains the entire p53 coding region (including 126 bp upstream of the ATC initiation codon). The nucleotide sequence shows a high degree of homology with the human (73%), murine (74%) and rat (66%) cDNAs. The encoded ovine p53 protein is 382 amino acids long with an apparant molecular weight of 50 kDa and shares 79% and 72% amino acid homology with the human and the mouse p53 respectively. Furthermore, the homology is not equally distributed along the molecule but is mainly located within live highly conserved regions. As its mouse and human counterparts, the ovine p53 contains a high proportion of proline residues, an acidic N-terminal domain and a basic C-terminal domain. We also report the structure of the ovine p53 gene that is similar to those already defined from other species.