What are the differences in the transcription between eukaryotes and prokaryotes?

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Accepted Answer

Transcription is the process by which the information stored in the DNA is transferred to an mRNA through RNA synthesis. Although the overall process and chemistry remains the same in both prokaryotes and eukaryotes, there are a few notable differences between the two.

Basis of differentiation

Prokaryotic Transcription

Eukaryotic Transcription

Definition

Refers to the transcription process that takes place in prokaryotic cells

Refers to the transcription process that takes place in eukaryotic cells

Order in which transcription and translation occur

Transcription and translation occur simultaneously

Transcription and translation do not occur simultaneously – they are two separate processes

Site of occurrence

Transcription occurs in the cytoplasm

Transcription occurs in the nucleus and translation occurs in the cytoplasm

Level of complexity

Process is relatively simple

Process is relatively complex

Variation in promoters

Less variation in promoters

More variation in promoters

Type of RNA polymerase involved

Involves a single type of RNA polymerase, which is comprised of a core enzyme and other subunits

Type of RNA polymerase varies according to the organisms
- RNA polymerase I, II, III are present in all eukaryotes, 
- RNA polymerase IV and V are present only in plants

Site of RNA release and processing

RNAs are released and processed in the cytoplasm

RNAs are released and processed in the nucleus

Number of polypeptides in RNA polymerases

RNA polymerases are a complex of five polypeptides or subunits

RNA polymerases are a complex of 10 -15 polypeptides or subunits

Transcription of mRNA

mRNA is transcribed directly from template DNA molecule

A pre-mRNA molecule known as a primary transcript is formed first and then processed to yield a mature mRNA

Type of Transcription

Transcription is indirect - A complex of DNA and histone proteins must be accessible for transcription to take place

Transcription occurs directly as DNA is not bound to the histone proteins

Type of mRNA sequence

mRNA sequence is polycistronic

mRNA sequence is monocistronic.

Transcription Terminators

Two types of transcription terminators - Rho-dependent terminators and Rho-independent terminators

The three RNA polymerases employ different mechanisms for the termination

Presence of post-transcriptional modifications

Absent

Present

Basis of differentiation	Prokaryotic Transcription	Eukaryotic Transcription
Definition	Refers to the transcription process that takes place in prokaryotic cells	Refers to the transcription process that takes place in eukaryotic cells
Order in which transcription and translation occur	Transcription and translation occur simultaneously	Transcription and translation do not occur simultaneously – they are two separate processes
Site of occurrence	Transcription occurs in the cytoplasm	Transcription occurs in the nucleus and translation occurs in the cytoplasm
Level of complexity	Process is relatively simple	Process is relatively complex
Variation in promoters	Less variation in promoters	More variation in promoters
Type of RNA polymerase involved	Involves a single type of RNA polymerase, which is comprised of a core enzyme and other subunits	Type of RNA polymerase varies according to the organisms RNA polymerase I, II, III are present in all eukaryotes, RNA polymerase IV and V are present only in plants
Site of RNA release and processing	RNAs are released and processed in the cytoplasm	RNAs are released and processed in the nucleus
Number of polypeptides in RNA polymerases	RNA polymerases are a complex of five polypeptides or subunits	RNA polymerases are a complex of 10 -15 polypeptides or subunits
Transcription of mRNA	mRNA is transcribed directly from template DNA molecule	A pre-mRNA molecule known as a primary transcript is formed first and then processed to yield a mature mRNA
Type of Transcription	Transcription is indirect - A complex of DNA and histone proteins must be accessible for transcription to take place	Transcription occurs directly as DNA is not bound to the histone proteins
Type of mRNA sequence	mRNA sequence is polycistronic	mRNA sequence is monocistronic.
Transcription Terminators	Two types of transcription terminators - Rho-dependent terminators and Rho-independent terminators	The three RNA polymerases employ different mechanisms for the termination
Presence of post-transcriptional modifications	Absent	Present

Basis of differentiation

Prokaryotic Transcription

Eukaryotic Transcription

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