TRANSCRIPTION REGULATION IN EUKARYOTES:
The regulation of gene expression is
eukaryotes differs in threee important ways typically found in bacteria-
eukaryotes differs in threee important ways typically found in bacteria-
1. The eukaryotes make use of gene regulatory proteins that can not act even when they are bound to dna
thousands of nucleotides way from the promoter that they influence and a single promoter can be
controlled by an almost ultimate no gene of regulatory seq. Scattered along the dna.
2. Only the eukaryotic rna poly.2 transcript all protein coading genes cannot initiate transcription on its
own. It requires a set of protein called general transcription factors which much be assembled at the promoter before starting the transcription.
3.The packing of eukaryotic dna in to chrimatin provides opportunities for regulation of transcription.
RESPONSE ELEMENTS Group of eukaryotic genes are under common control and they share a promoter elements that is
recognised by a regulatory transcription factors. An element that cause a gene to response to such a regulatory transcription factors is called response elements. They have the same general characteristics as
upstream elements of promoter and enhance contain short consequences. The response elements found in different. Genes are closely related but may not be identical.
The dna sites to which the eukaryotic gene activator found were originally termed as enhancers since their presence enhance or increases the rate of transcription dramatically. Promoter is a region where rna poly. And trans. Factors were assembled.
The response elements may be located in promoter or in enhancers eg. On HSE is found in promoter while GRE is found in enhancer. A gene is regulated by a sequence at promoter or enhancers that is recognised by a specific protein. This protein is function as a transcription Factors needed for rna polymerase to initiate
transcription.