Abstract
The thermostability of thermophilic enzymes makes them ideal for use in biotechnology and medical science research. The overexpression of heterogeneous genes from thermophiles, such as the mesophilic Deinococcus geothermalis, in Escherichia coli is a genetic engineering technique for producing stable and useful proteins. In our previous study, 1- or 2-base expansion of the Shine-Dalgarno sequence, which is a ribosome-binding site in mRNA, was effective for the overexpression of the nicotinamide adenine dinucleotide oxidase gene from Deinococcus. geothermalis in Escherichia coli. In the present study, we examined the effect of expanding the Shine-Dalgarno sequence of the malate dehydrogenase gene and three genes from the aldehyde dehydrogenase family. Our results revealed that a 1- or 2-base expansion of the Shine-Dalgarno sequence was effective for the overexpression of all genes from Deinococcus geothermalis in Escherichia coli. However, the effects of the expansion of Shine-Dalgarno sequence from 3 to 5 bases were different between these genes.