The Analysis of Promoters and the Effective Expression of Exogenous Proteins in a Cold-adapted Bacterium

Abstract:

Based on the constructed promoter probe vectors that could replicate both in E. coli and in a cold-adapted bacterium, several candidate promoters were isolated and their activities were evaluated by RT-PCR. The transcription initiation sites and core sequence of promoters were determined by primer extension analysis. A low-temperature expression vector was constructed by using the strongest promoter and a thermolabile a-amylase gene was successfully overproduced under control of this promoter at low temperature (7℃), while the secreted a-amylase amounted up to 35% of the total extracellular proteins. The expression system is expected to be useful for the production of thermolabile exogenous proteins at low temperatures.