The nucleotide sequence of the chicken thymidine kinase gene and the relationship of its predicted polypeptide to that of the vaccinia virus thymidine kinase.

The entire DNA nucleotide sequence of a 3.0 kilobase pair Hind III fragment containing the chicken cytoplasmic thymidine kinase gene was determined. Oligonucleotide linker insertion mutations distributed throughout this gene and having known effects upon gene activity ( Kwoh , T.J., Zipser , D., and Wigler , M. 1983. J. Mol. Appl. Genet. 2, 191-200), were used to access regions of the Hind III fragment for sequencing reactions. The complete nucleotide sequence, together with the positions of the linker insertion mutations within the sequence, allows us to propose a structure for the chicken thymidine kinase gene. The protein coding sequence of the gene is divided into seven small segments (each less than 160 base pairs) by six small introns (each less than 230 base pairs). The proposed 244 amino acid polypeptide encoded by this gene bears strong homology to the vaccinia virus thymidine kinase. No homology with the thymidine kinases of the herpes simplex viruses was found.