Difference in regulation of bacterial and eukaryotic genes:
In bacterial cells, genetic regulation maintains internal biochemical flexibility in response to changing environmental conditions by turning off and on of genes. This flexibility enables expression of only a subset of genetic information, which is appropriate for the given environment.
Eukaryotic gene regulation is more complex than the prokaryotic gene regulation. Eukaryotes are multicellular organisms, consisting of different cell types. Each cell in a eukaryotic organism has different and specialized function. Each cell differentiates by activating different subset of genes. Because of the multitude of cell types gene regulation in eukaryotes is more complex. Regulation of eukaryotic genes can occur during transcription, RNA processing, and also during translation.
Thus, enhancers are responsible, for increasing the transcription levels and are also responsible, for regulating tissue or cell specific transcription.
Many DNA-protein interactions are shared by prokaryotes and eukaryotes, but the mechanism by which proteins bound to DNA at great distance from the start of transcription affect that transcription is unique to eukaryotes. Also, mechanisms of gene regulation based on chromatin structure are distinctly eukaryotic.