INTRODUCTION HISTORY WHAT IS TRANSCRIPTION PROKARYOTIC TRANSCRIPTION STEPS OF TRANSCRIPTION HOW TRANSCRIPTION OCCURS PROCESS OF TRANSCRIPTION Initiation Elongation Termination CONCLUSION REFRENCES

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

2.  INTRODUCTION
 HISTORY
 WHAT IS TRANSCRIPTION
 PROKARYOTIC TRANSCRIPTION
 STEPS OF TRANSCRIPTION
 HOW TRANSCRIPTION OCCURS
 PROCESS OFTRANSCRIPTION
 Initiation
 Elongation
 Termination
 CONCLUSION
 REFRENCES
PROKARYOTIC TRANSCRIPTION

3.  Transcription is the flow of an information
process from DNA to RNA and from RNA to
protein. It is the process of creating
a complementary RNA copy of a sequence
of DNA.
 . During transcription, a DNA sequence is
read by an RNA polymerase, which produces
a complementary, antiparallel RNA strand.
PROKARYOTIC TRANSCRIPTION

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.
PROKARYOTIC TRANSCRIPTION

5.  DNA transcription is a process that involves
the transcribing of genetic information
from DNA to RNA.The transcribed DNA
message is used to produce proteins.
 DNA is housed within the nucleus of
our cells.
 It controls cellular activity by coding for the
production of enzymes and proteins.

6.  RNA polymerase binds to DNA.
 RNA polymerase transcribes a single
strand of DNA into a single stranded
RNA polymer called messenger RNA
(mRNA).
 RNA polymerase releases the mRNA
polymer and detaches from the DNA.
PROKARYOTIC TRANSCRIPTION

7.  Prokaryotic transcription is the process in
which messenger RNA transcripts of genetic
material in prokaryotes are produced, to be
translated for the production of proteins.

9. PROKARYOTIC TRANSCRIPTION

10.  It completes in 3 steps:-
 Initiation
 Elongation
 Termination

11.  At the start of initiation,
the core enzyme is
associated with a sigma
factor that aids in finding
the appropriate -35 and -10
base pairs downstream of
promoter sequences.
 RNA polymerase (RNAP)
binds to one of several
specificity factors, σ, to
form a holoenzyme
 In this form, it can
recognize and bind to
specific promoter regions
in the DNA.
PROKARYOTIC TRANSCRIPTION

12.  The DNA is unwound and becomes
single-stranded ("open") in the
vicinity of the initiation site (defined
as +1).This holoenzyme/unwound-
DNA structure is called the open
complex.
 The RNA polymerase transcribes the
DNA (the beta subunit initiates the
synthesis), but produces about 10
abortive (short, non-productive)
transcripts which are unable to leave
the RNA polymerase because the
exit channel is blocked by the σ-
factor.
 The σ-factor eventually dissociates
from the holoenzyme, and
elongation proceeds.
PROKARYOTIC TRANSCRIPTION

13.  As transcription
proceeds, RNA
polymerase traverses
the template strand
and uses base pairing
complimentarily with
the DNA template to
create an RNA copy
PROKARYOTIC TRANSCRIPTION

14. Rho-independent
transcription
termination) involves
terminator sequences
within the RNA that
signal the RNA
polymerase to stop.
It forms a stem loop
hairpin structure that leads
to the dissociation of
tRNAP from the DNA
template.
PROKARYOTICTRANSCRIPTION

15.  It uses a termination
factor called ρ factor(rho
factor) which is a protein to
stop RNA synthesis at specific
sites.
 This protein binds at a rho
utilisation site on the nascent
RNA strand and runs along
the mRNA towards the RNAP.
 A stem loop structure
upstream of the terminator
region pauses the RNAP,
when ρ-factor reaches the
RNAP, it causes RNAP to
dissociate from the DNA,
terminating transcription
PROKARYOTIC TRANSCRIPTION

16.  Transcription is a flow of information from
DNA to RNA and from RNA to protein.The
information in DNA is not directly converted
into proteins, but must first be copied into
RNA.This ensures that the information
contained within the DNA does not become
tainted. . It controls cellular activity by coding
for the production of enzymes and proteins.
PROKARYOTIC TRANSCRIPTION

17.  J.D.Watson
 Gerald karp ( cell and molecular biology)
 www.google.com