Temperature dependence of transcriptional activity of yeast 3-phosphoglycerokinase promoter in Escherichia coli

Abstract

We have studied the activity of yeast PGK promoter in E. coli at different temperatures using lacZ as the reporter gene. The B-galactosidase activity was found to be less at 42 degrees C than at 30 degrees C. Northern blot analysis showed that the level of lacZ transcript was less in recombinant cells grown at 42 degrees C, whereas plasmid copy number per cell was more as compared to recombinant cells grown at 30 degrees C. Data suggest that the yeast PGK promoter is less active at 42 degrees C and that this activity is regulated at the level of transcription.