| 摘要 |
PURPOSE:To obtain a protein changed to a theromostable protein by transforming a thermophilic bacterium of the genus Thermus deficient in a selected marker gene with a DNA containing a selected marker gene and a thermostable structural gene and subjecting to homologous site transformation to manifest a gene. CONSTITUTION:A highly thermophilic bacterium of the genus Thermus deficient in a gene capable of becoming a selected marker gene is transformed with a DNA containing a DNA fragment having the selected marker gene and a nonthermophilic structural gene (e.g. isopropylmalic dehydrogenase gene derived from bacterium of the genus Bacillus) sandwiched by a flanking range of the selected marker gene, subjected to homologous site transformation, heated, a transformant to manifest the selected marker gene and the nonthermophilic structural gene is selected, further the transformant is cultured, a protein encoding the nonthermophilic structural gene is made into chimera and a thermophilic protein (e.g. thermophilic isopropylmalic dehydrogenase) is manifested to give the objective protein. |
