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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

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket 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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