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Difference between Prokaryotic and Eukaryotic Transcription

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Last updated date: 28th Feb 2024
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Prokaryotic and Eukaryotic Transcription (Introduction)

Transcription is a vital process for both eukaryotic as well as prokaryotic cells. But, is it the same for both of them? It most certainly isn't! There are tons of differences between prokaryotic and eukaryotic transpiration. These fundamental differences will help strengthen your concepts of prokaryotic and eukaryotic transcription, concerning one another. So, read the article below and get your concept right!


What is Prokaryotic and Eukaryotic Transcription? 

To explain prokaryotic and eukaryotic transcription and their differences, it’s mandatory to understand them. Why? Because only by understanding them individually can we understand the differences between prokaryotic and eukaryotic transcription. So, keep reading to learn the characteristics of prokaryotic and eukaryotic transcription.


Prokaryotic Transcription

It is the process by which a prokaryotic organism's genetic information in a cell is transcribed into RNA molecules. The beginning of prokaryotic transcription starts when RNA polymerase binds to the DNA template at the promoter region. Through it, by unwinding the DNA double helix using RNA polymerase, complementary RNA strands are synthesized. These are synthesised based on the DNA template's nucleotide sequence. It is all under the elongation part of the transcription process and ends on reaching a terminal signal.


Although a process complex for prokaryotes, prokaryotic transcription is still nowhere near as complex as eukaryotic transcription. 


Eukaryotic Transcription

A crucial process to convert genetic information from DNA to functional RNA molecules in eukaryotes is Eukaryotic Transcription. It occurs in three main steps- initiation, elongation, and termination. And they all take place in a eukaryotic cell's nucleus. The enzyme that facilitates this process in eukaryotes is RNA polymerase II. It does so by recognising promoters (specific DNA sequences). Other than that, the transcription factors play a crucial role by ensuring proper initiation through recruiting RNA polymerase.


The RNA molecule's functionality and stability are kept intact post-transcription by RNA splicing, and capping. It's another aspect that makes eukaryotic transcription different from prokaryotic transcription.


Difference between Prokaryotic and Eukaryotic Transcription

Do you always wonder about the prokaryotic and eukaryotic transcription difference? Then the table below will cover all your doubts regarding the prokaryotic and eukaryotic transcription- differences


S. No. 

Category

Procaryotic Transcription

Eukaryotic Transcription

1

Location

Occurs in the cytoplasm

Occurs in the nucleus

2

DNA Complexity

Single circular chromosome

Multiple linear chromosomes

3

Transcription Machinery

RNA polymerase and sigma factor

RNA polymerase and transcription factors

4

Promoter Recognition

Recognises specific DNA sequences (consensus sequences)

Recognises core promoter elements, enhancers, and other regulatory elements

5

Enzymes

RNA Polymerases I, II, III

Single RNA Polymerase

6

Transcription Start Site

Often lacks a defined start site

Has a defined start site (TATA box or initiator element)

7

Number of polypeptides

Five 

Ten to Fifteen

8

Transcription Termination

Usually involves a hairpin loop followed by a string of uracil (U) bases

Involves cleavage and polyadenylation of the pre-mRNA

9

Transcriptional Units

Operons are common

Operons are rare or absent

10

Transcription Factors

Few transcription factors involved

Multiple transcription factors involved

11

RNA Processing

Minimal processing of mRNA

Extensive processing of mRNA

12

Splicing

Generally no introns or splicing

Introns are common and undergo splicing

13

RNA Stability

mRNA is generally less stable

mRNA is more stable

14

mRNA Export

Can be translated immediately

Requires processing and export to the cytoplasm

15

Translation Coupling

Transcription and translation occur simultaneously

Transcription and translation are spatially separated

16

Post Transcriptional Regulation 

Limited regulatory mechanisms

Extensive regulatory mechanisms (e.g., alternative splicing, RNA editing)

17

Transcription Rate

Generally higher

Generally lower

18

Complexity Control

Few regulatory mechanisms

Extensive regulatory mechanisms


Similar Characteristics of Prokaryotic and Eukaryotic Transcription 

Although there are significant differences between eukaryotic and prokaryotic transcription processes, there are also some notable similarities:


1. Initiation: Both eukaryotic and prokaryotic transcription involve the recognition of specific DNA sequences to initiate transcription. In prokaryotes, a sigma factor assists RNA polymerase in binding to the promoter region, while in eukaryotes, transcription factors aid in promoter recognition.


2. Elongation: Both eukaryotic and prokaryotic transcription involve the synthesis of RNA by RNA polymerase moving along the DNA template strand, adding nucleotides to the growing RNA molecule.


3. Termination: In both eukaryotes and prokaryotes, transcription is terminated by specific signals. Prokaryotes typically have two termination mechanisms: rho-dependent termination, where a protein called rho assists in transcription termination, and rho-independent termination, which involves specific DNA sequences. Eukaryotes use polyadenylation signals and termination factors to terminate transcription.


4. RNA Processing: In both eukaryotes and prokaryotes, the newly synthesized RNA molecules undergo processing steps. In prokaryotes, mRNA molecules are typically ready for translation immediately after transcription. In eukaryotes, however, mRNA undergoes additional processing steps, such as RNA splicing to remove introns, the addition of a 5' cap, and the addition of a poly-A tail.


Conclusion

Conclusively, on reading the above article, you will have no doubts about the difference between prokaryotic and eukaryotic transcription. Not only that, but you'll be able to explain prokaryotic and eukaryotic transcription alongside categorically differentiating them. Is that all? No! This article also provides you with a guide to similarities shared between both prokaryotic and eukaryotic transcription. Therefore, it's a perfect guide to understanding the relationship between prokaryotic and eukaryotic transcription.

FAQs on Difference between Prokaryotic and Eukaryotic Transcription

1. What mechanism is shown in the transcription in prokaryotes?

For transcription, the entire mechanism of transcription takes place in the cytoplasm of the respective cell. When it comes to the steps involved in the prokaryotic transcription they are divided into three major steps- Initiation, elongation, and termination. Wherein in the initiation phase, the RNA Polymerase starts its work by recognizing the promoter sequence in the available DNA strand. With this, the DNA strand unwinds, and transcription starts (elongation). It continues till it reaches the site of termination.

2. How is transcription in prokaryotes and eukaryotes regulated?

The regulation of transcription in prokaryotes and eukaryotes occurs in different ways. In prokaryotic transcription, both translation and transcription occur simultaneously. The regulation of this transcription is conducted on a transcriptional level. But when it comes to eukaryotic transcription, eukaryotic gene expression is regulated while RNA processing and transcription. Here RNA processing takes place in the cell's nucleus while protein translation is in the cytoplasm.

3. Do you know the 4 differences between prokaryotes and eukaryotes?

Yes. Here are the four very prominent differences between eukaryotes and prokaryotes:


1. There are cell-membrane-bound organelles present in eukaryotes. An example is- the nucleus. When it comes to prokaryotes, there are no cell-membrane-bound organelles. 

2. In prokaryotes, the cytoplasm is home to the genetic material. But it is not true for eukaryotes because their genetic material is located in the cell's nucleus. 

3. A prokaryotic cell's structure is smaller and less complex. When it comes to eukaryotic cell it has a complex and larger structure. 

4. The DNA in prokaryotes is circular and without association with histone (a protein) but DNA in eukaryotes is tightly coiled and linear (in association with histone).