CATTLE LEUKEMIA VIRUS MUTANT TAX GENE

摘要

PROBLEM TO BE SOLVED: To obtain a new cattle leukemia virus mutant tax gene which encodes a mutant gene product having mutation in a specific site of the gene product of cattle leukemia virus tax gene and possesses a function of facilitating the proliferation of cattle leukemia virus or its homologous retrovirus. SOLUTION: This cattle leukemia virus mutant tax gene is a new mutant tax gene encoding a mutant gene product containing one or more mutations selected from the group consisting of the following mutations: the replacement of No.240 serine with threonine, the replacement of No.247 aspartic acid with glycine, the replacement of No.251 threonine with alanine, the replacement of No.258 aspartic acid with glycine, the replacement of No.261 histidine with tyrosine and the replacement of No. 265 serine with glycine on the gene product of cattle leukemia virus tax gene and possesses the function of facilitating the proliferation of cattle leukemia virus or its homologous retrovirus. This gene is obtained by mutating Escherichia coil or the like having a wide-type gene by the use of a medicine followed by recovering the gene from the microbial cell body.