Abstract
We investigated the protein productivity of the promoters for genes showing prolonged induction upon cold shock in Escherichia coli. Six low temperature inducible genes (frdA, glpB, hypB, katG, nupG, ompT) were selected based on the previously reported cDNA microarray based global transcription profiling of Escherichia coli Kl2 in response to cold shock. Their promoter regions were isolated from the genomic DNA of E. coli JM109 and expression levels induced by the promoters were examined by using green fluorescence protein (GFP) as a reporter at $15^{\circ}C$ and $37^{\circ}C$. Among the six promoters, the promoter for nupG showed the highest and prolonged expression at both temperatures and the cold inducibility of nupG promoter was not observed.
본 연구에서는 저온에서 발현이 유도되고 지속적으로 발현된다고 알려진 대장균의 6개의 유전자 (frdA, glpB, hypE, katG, nupG, ompT)에 대한 promoter의 단백질 생산성을 알아보기 위하여 GFP를 reporter 단백질로 이용하여 각각의 promoter들에 대한 $37^{\circ}C$와 $15^{\circ}C$에서의 발현도와 저온 유도성에 대하여 고찰하였다. nupG promoter의 경우 $37^{\circ}C$와 $15^{\circ}C$ 모두에서 지속적인 유전자 발현도를 보였으나 promoter에 의한 저온 유도성은 없는 것으로 판별되었다.