The document summarizes the structure of eukaryotic promoters. It describes the three main portions that make up a promoter: the core promoter, proximal promoter, and distal promoter. The core promoter contains elements like the TATA box and transcription start site. The proximal promoter is upstream and binds general transcription factors. The distal promoter regulates transcription. Eukaryotic promoters are more complex than prokaryotic ones, spanning different DNA sequences and using enhancers. The TATA box, CAAT box, and GC box are also discussed.

1. STRUCTURE OF
EUKARYOTIC PROMOTER
Submitted by:
AKASH.A
22MAB04`
I M.Sc., Marine Biology
Department of Marine and Coastal Studies
Madurai Kamaraj University

2. https://youtu.be/gG7uCskUOrA

3.  A promoter is a region of DNA where transcription of a gene is
initiated.
 Promoters are a vital component of expression vectors because
they control the binding of RNA polymerase to DNA.
 RNA polymerase transcribes DNA to mRNA which is
ultimately translated into a functional protein.
 Thus the promoter region controls when and where in the
organism your gene of interest is expressed.

4. https://images.app.goo.gl/dduyefEovCpb1VAp6

5. There are three main portions that make up a
promoter:
 Core promoter
 Proximal promoter
 Distal promoter

6.  The core promoter region is located most proximal to
the start codon and contains the RNA polymerase
binding site, TATA box, and transcription start site
(TSS).
 RNA polymerase will bind to this core promoter
region stably and transcription of the template strand
can initiate.

7.  Further upstream from the core promoter you will
find the proximal promoter which contains many
primary regulatory elements.
 The proximal promoter is found approximately
250 base pairs upstream from the TSS and it is the
site where general transcription factors bind.

8.  The final portion of the promoter region is called
the distal promoter which is upstream of the
proximal promoter.
 The distal promoter also contains transcription
factor binding sites, but mostly contains regulatory
elements.

9.  Eukaryotic promoters are much more complex and diverse
than prokaryotic promoters.
 Eukaryotic promoters span a wide range of DNA
sequences.
 It is not unusual to have several regulatory elements such
as enhancers several kilobases away from the TSS.

10.  Eukaryotic promoters are so complex in structure that
the DNA tends to fold back on itself which helps to
explain how many physically distant DNA sequences can
affect transcription of a given gene.
 The TATA-binding protein binds the TATA box and helps
in the subsequent binding of the RNA polymerase.
 A transcription complex is constructed from the RNA
polymerase and several transcription factor proteins.

11. https://images.app.goo.gl/sco6nLNawgE6QQzt6

12. TYPES OF RNA POLYMERASES
RNA polymerase I
RNA polymerase II
RNA polymerase III

13. RNA polymerase I
transcribes genes encoding ribosomal RNA (rRNA) which is a main
component of a cell’s ribosome structure. Ribosomes are the site of
protein synthesis where mRNA is translated into a protein.
RNA polymerase II
transcribes messenger RNA (mRNA) which is the RNA responsible
for providing a stable template for the translation of a protein.
RNA polymerase III
transcribes genes encoding transfer RNAs (tRNA), the adaptor
molecules that are responsible for bringing amino acids to the
ribosome when proteins are being synthesized.

14. https://images.app.goo.gl/2qJarXP19f3rJPdaA

15. TATA BOX
 TATA box is a DNA sequence that indicates where a genetic sequence can
be read and decoded.
 Transcription is a process that produces an RNA molecule from a DNA
sequence.
 The TATA box is named for its conserved DNA sequence, which is most
commonly TATAAA.
 Many eukaryotic genes have a conserved TATA box located 25-35 base
pairs before the transcription start site of a gene.
 The TATA box is able to define the direction of transcription and also
indicates the DNA strand to be read.
 Proteins called transcription factors can bind to the TATA box and recruit an
enzyme called RNA polymerase, which synthesizes RNA from DNA.

16. CAAT BOX
 CCAAT box (also sometimes abbreviated a CAAT
box or CAT box) is a distinct pattern of nucleotides with
GGCCAATCT consensus sequence that occur upstream by
60–100 bases to the initial transcription site.
 It is an invariant DNA sequence at about minus 70 base pairs
from the origin of transcription in many eukaryotic promoters.

17. GC BOX
 GC box is a distinct pattern of nucleotides found
the promoter region of some eukaryotic genes.
 The GC box is upstream of the TATA box, and approximately
100 bases upstream from the transcription initiation site.
 The GC box is commonly the binding site for zinc
finger proteins. An alpha helix section of the protein
corresponds with a major groove in the DNA.

18. ·https://www.addgene.org/mol-bio-reference/promoters/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6205604/
https://en.wikipedia.org/wiki/Promoter_(genetics)