with the plasmid vector system described above. The transformant with the gene could not grow at 50℃ without leucine because of the instability of the gene product. A candidate of the stabilized mutant enzyme has been selected at higher temperature. This is the first example showing the expression and stabilization of an eukaryotic gene product in an extreme thermophile and will lead to the better understanding of the structural requirements for creating the enzymes with high stability.
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