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Properties of eukaryotic transcription

  • Complex!
  • RNA polymerase is the main protein that creates the RNA transcript
  • Proteins called transcription factors help RNA polymerase and regulate it's function.
  • 2 types of transcription factors: basal tfs and modulatory tfs.
  • Basal transcription factors - required for all transcription events.
  • Modulatory transcription factors - regulate expression of genes. Both positive and negative regulation.
  • Transcription factors can act from relatively far away. Up to 10kb!
  • pre-mRNA transcripts are spliced to remove exons.
  • Alternative splicing allows the cell to combine exons differently in the final mRNA transcript from the same pre-mRNA transcript.

Transcription in five easy steps

  • Transcription of DNA to pre-mRNA. DNA, RNA polymerase and transcription factors.
  • Addition of 5' methyl guanosine cap to pre-mRNA transcript.
  • Splicing of pre-mRNA transcript (yields mRNA proper)
  • Addition of 3' poly(A) tail to mRNA transcript.
  • mRNA is transported to the cytoplasm.

5 steps of mrna preparation

Rna polymerase - main protein that creates rna transcript.

RNA polynmerase is the protein whose job it is to 'read' the genetic code and create a complimentary RNA transcript from that code. Eukaryotes have three different types of RNA polymerases: RNA polymerase I, II, and III. RNA polymerase II is the from of polymerase that transcribes most genes and is the form of polymerase with which we need to concern ourselves.

Initiation of transcription

Transcription initiation in eukaryotes is complicated, and the details are not entirely understood (although we do have a good grasp on the basic mechanism). The fully assembled eukaryotic transcription inititation complex contains more than 50 polypeptides. RNA polymerase II has more than 10 polypeptide subunits by itself. Keep in mind that the process outlined below is a generalization, and any given, specific transcription event will probably vary some in the details. For example, although the TATA box is the most strongly conserved promoter sequence, it is by no means present in every eukaryotic promoter. Also, there is some debate as the importance of the order of the binding of the proteins in the initiation complex: it was thought that a specific order was vital, now, however, new evidence suggests that reaching the end binding state may be what is really important, whatever the order.

Transcription factors - help/regulate rna polymerase's function

Transcription factors (tfs) are proteins involved with transcription - except for RNA polymerase. Transcription factors can be broken down into two groups: basal tfs and modulatory tfs. Eukaryotic RNA polymerases are not capable of initiating transcription alone, they require the assistance of a set of basal transcription factors. Basal tfs assist RNA polymerase in the recognition of promoter sequences and unwiding the DNA double helix, among other functions. Basal tfs are necessary for every transcription event. Modulatory transcription factors regulate the expression of a gene, or a set of gene. These tfs are important because they allow the body to differentially express genes at different times and different places in the body. Modulatory tfs are vital for multicellular life. They allow the body to create different cells, tissues, and organs.

Questions & Answers

what is biology
Hajah Reply
the study of living organisms and their interactions with one another and their environments
AI-Robot
what is biology
Victoria Reply
HOW CAN MAN ORGAN FUNCTION
Alfred Reply
the diagram of the digestive system
Assiatu Reply
allimentary cannel
Ogenrwot
How does twins formed
William Reply
They formed in two ways first when one sperm and one egg are splited by mitosis or two sperm and two eggs join together
Oluwatobi
what is genetics
Josephine Reply
Genetics is the study of heredity
Misack
how does twins formed?
Misack
What is manual
Hassan Reply
discuss biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles
Joseph Reply
what is biology
Yousuf Reply
the study of living organisms and their interactions with one another and their environment.
Wine
discuss the biological phenomenon and provide pieces of evidence to show that it was responsible for the formation of eukaryotic organelles in an essay form
Joseph Reply
what is the blood cells
Shaker Reply
list any five characteristics of the blood cells
Shaker
lack electricity and its more savely than electronic microscope because its naturally by using of light
Abdullahi Reply
advantage of electronic microscope is easily and clearly while disadvantage is dangerous because its electronic. advantage of light microscope is savely and naturally by sun while disadvantage is not easily,means its not sharp and not clear
Abdullahi
cell theory state that every organisms composed of one or more cell,cell is the basic unit of life
Abdullahi
is like gone fail us
DENG
cells is the basic structure and functions of all living things
Ramadan
What is classification
ISCONT Reply
is organisms that are similar into groups called tara
Yamosa
in what situation (s) would be the use of a scanning electron microscope be ideal and why?
Kenna Reply
A scanning electron microscope (SEM) is ideal for situations requiring high-resolution imaging of surfaces. It is commonly used in materials science, biology, and geology to examine the topography and composition of samples at a nanoscale level. SEM is particularly useful for studying fine details,
Hilary
cell is the building block of life.
Condoleezza Reply
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Source:  OpenStax, Statistical machine learning for computational biology. OpenStax CNX. Oct 14, 2007 Download for free at http://cnx.org/content/col10455/1.2
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