Cloning transforming genes from human papillomavirus type 18

: Nucleotide sequences of type 18 human papilloma virus genes E6 and E7 inserted in human DNA cloned from cervical tumor are determined. The resultant sequences are compared to the prototype variant. Five point mutations not leading to replacement of amino acid residues in polypeptide chain and 1 substituting the amino acid in codon 129 are detected in gene E6 sequence. In E7 sequence, one significant mutation in codon 92 is detected. Both substitutions of asparagine for lysine are localized in the 3'-terminal region of the genes, which may not affect the transforming potential of these sequences. DNA fragments of E6 and E7 coding regions obtained by PCR were independently cloned in bifunctional expression vector DelpC7. The identity of hybrid E6 and E7 nucleotide sequences to initial ones is verified by sequencing.