Abstract
Thermostable enzymes have applications in biosensors and bioreactors. Overexpression of thermostable enzyme-encoding genes from thermophiles in Escherichia coli is necessary to produce sufficient quantities of such enzymes. Deinococcus gerthermalis is a moderately thermophilic bacterium and has moderately thermostable enzymes. Nicotinamide adenine dinucleotide (NADH) is an important coenzyme for various dehydrogenases. NADH oxidase (Nox) catalyze the oxidation of NADH. Therefore, Nox is a versatile enzyme that can be used in combination with many types of biosensors. This study reveals the effect of expansion of the SD sequence in the leader sequence of NADH oxidase gene from D. geothermalis for overexpression in E. coli, and shows that while 1- or 2-bases expansion of the Shine-Dalgarno sequence is effective. This study should be contributed to the expression of many genes in E. coli.