ENHANCERS OR PROMOTERS:

 

      

Most of gene requires enhancers for this transcription. They determine Differential transcription is a cell types and time. The function by providing multiple signals to the promoter whether a given gene is transcribed.

The interactions between protein bound to enhancers sites and Transcription initiation complex assembled at the promoter is through the regulator transcription . A gene can have several enhancer elements and
each turning it on in a different sets of gene.

SILENCER:Enhencers can also be used to inhibit transcription. In some cases the sam transcription factors that activated the transcription of one gene can be used to repress the transcription of other genes.
These are called enhencer.

ACTIVATOR: The activator protein binds to the regusltory sites on dna near the promoter region and acts as a switch which gets on and off. Its binding facilitate rna polymerase actively and transcription of near genes.

In eukaryotes activators have a diff. target molecule that they can recruit in order to promote gene transcription. They can recruit other transcription factors and cofactors needed for transcription initiation.

REPRESSOR: Eukaryotes use gene repressor Protein to regulate transcription of their genes. The repressor molecule employees various ways like competitive binding masking activator surface interacts with transcription factor etc to repress the transcription.