Question

what is the difference between the functions of general transcription factors (GTFs), common activators such as Sp1 and Oct1, and enhancer-binding activators such as Gal4 in eukaryotes? make sure to specify where they bind and under what conditions they affect transcription initiation.

Answer 1

Transcription factors are the proteins other than RNA polymerase involved in the initiation of the transcription process. General Transcription Factors are defined as proteins that bind with the DNA at the promoter region and enhance the transcription process.

Activators has a DNA binding domain and an activation domain. Common activators like Sp1, Oct1 does not bind at the promoter region, but they bind close to the promoter region and recruits the RNA polymerase and other transcription factors at the promoter site for transcription initiation. These factors are activated by different signaling pathways and translocated in the nucleus for function.

Enhancer binding activators bind at the remote region from the promoter but they are very strong activators of the transcription initiation by recruiting the RNA polymerase and other factors. They generally remain repressed by other factors and become activated when the repression is removed by the environmental cues.