INTRODUCTION. HISTORY. PROCESS OF TRANSCRIPTION. STAGES OF TRANSCRIPTION. ENZYME INVOLVES IN TRANSCRIPTION. TERMINATION. PROKARYOTES. Transcription terminators. EUKARYOTES. Two models for termination. CONCLUSION. REFERENCES.

1. transcrip tion termination
By
KAUSHAL KUMAR SAHU
Assistant Professor (Ad Hoc)
Department of Biotechnology
Govt. Digvijay Autonomous P. G. College
Raj-Nandgaon ( C. G. )

2. • INTRODUCTION.
•HISTORY.
•PROCESS OF TRANSCRIPTION.
•STAGES OF TRANSCRIPTION.
•ENZYME INVOLVES IN
TRANSCRIPTION.
•TERMINATION.
•PROKARYOTES.
Transcription terminators.
•EUKARYOTES.
Two models for termination.
•CONCLUSION.
•REFERENCES.
SYNOPSIS

3. •INTRODUCTION
TRANSCRIPTION:-
•Transcription involves synthesis of an RNA chain
representing one strand of a DNA duplex.
•By "representing" we mean that the RNA is identical in
sequence with one strand of the DNA, which is called
the coding strand.
•It is complementary to the other strand, which provides
the template strand for its synthesis.
•Recapitulates the relationship between double-stranded
DNA and its single-stranded RNA transcript.

4. •A molecule that allows the genetic material to be realized as
a protein was first hypothesized by François Jacob and Jacques
Monod.
•RNA synthesis by RNA polymerase was established in vitro by
several laboratories by 1965; however, the RNA synthesized by
these enzymes had properties that suggested the existence of
an additional factor needed to terminate transcription
correctly.
•In 1972, Walter Fiers became the first person to actually
prove the existence of the terminating enzyme.
•Roger D. Kornberg won the 2006 Nobel Prize in
Chemistry "for his studies of the molecular basis of eukaryotic
transcription".
HISTORY

5. •PROCESS OF TRANSCRIPTION:-

6. •STAGES OF TRANSCRIPTION:-
•Mainly three stages
of transcription:-
•Initiation :- RNA
polymerase initiates
transcription after
binding to a promoter
site on DNA.
•Elongation:- During
elongation the
transcription bubble
moves along DNA and
the RNA chain is
extended in the 5'-3'
direction.
•Termination :-
Transcription stops, the
DNA duplex reforms and
RNA polymerase
dissociates at a
terminator site.

8. •ENZYME INVOLVES IN BOTH EUKARYOTES
AND PROKARYOTESTANSCRIPTION:-

9. In eukaryotes transcription factors required for
RNA polymerase-II
Basal transcription factor: TFFIIA, TFIIB, TFIID, TFIIE,
TFIIF,TFIIH, TFIIJ. these are present in all Promoters.
Upstream transcription factor:-they are present in left side
of starting point and present in all the transcriptional cells.
Regulatory transcription factor:-they work as a upstream
factor and help to regulation of transcription process.
Promoters:-
They are promote the transcription correctly.
In case of RNA Pol-II following modules are given:-
Initiator, TATA Box, CAATBox, GCBox, Octamer
sequence.

10. •Termination also called the ending process of
transcription, were the transcribed RNA released from the
double stranded DNA.
TERMINATION
•TERMINATION IN PROKARYOTES
Intrinsic or Rho-independent
transcription termination
Rho-dependent transcription
terminaton
EUKARYOTIC TRANSCRIPTION
TERMINATION

11. Intrinsic or Rho-independent transcription termination
•Intrinsic terminators have the two
structural features evident in Figure
9.47: a hairpin in the secondary
structure; and a region that is rich in
U residues at the very end of the
unit.
•Both features are needed for
termination. The hairpin usually
contains a G-C-rich region near the
base of the stem.

12. •Rho-dependent transcription terminaton
STRUCTURE OF Rho -terminator

13. •Rho-dependent transcription terminaton

14. •EUKARYOTIC TRANSCRIPTION TERMINATION
PROCESS:-Polyadnylation of 3’ end of mRNA:

15. •EUKARYOTIC TRANSCRIPTION TERMINATION:-

16. •Torpedo.
•Allosteric.
•Torpedo:- a portion of mRNA is left along with
RNA Pol after the cleavage termination occurs
when RNA removed from DNA template
A protein present on the end of the
mRNA known as Rat(in Yeast) and
Hxrn2(in human).
When this protein receive signal that
cleavage is done and the portion is
uncapped it will come and bind to this
region(5’) to (3’) end.
It goes on degrading the RNA till it finds
the RNA Pol portion where the RNA Pol is
transcribing the mRNA.
After degradation it dissociate from
template and RNA Pol also leaves the
DNA template.
This enzyme is already
loaded in the Pol before
attechment of poly ‘A’
uncapped
5’ 3’
DNA template
•TWO MODELS ARE ACEPTED FOR THE
TERMINATION OF EUKARYOTES:-

17. it explain only the steric changes of the complex.
Termination depends on steric.
Due to the steric changes RNA cleave out from the
template and the RNA Pol also come out from DNA
template.
Allosteric

18. •REFERENCES:-
BOOKS- WRITER-
•GENE-VIII Benjamin Lewin
•Molecular biology of the gene J. D. Watson,
•Molecular biology of the cell Alberts
•Cell and molecular biology 5th edition Gerald Karp
•www.wikipedia.com
N.H. Hopkins