10 Eukaryotic Transcription

Question 1

What are problems encountered in eukaryotic transcription that are not found in prokaryotic transcription?

Answer 1

Histones
Long sequences
Introns

Question 2

How is transcription in Eukaryotes different from Prokaryotes?

Answer 2

1. Number of RNA polymerases
   Bacterial have 1
   Eukaryotes use at least 3
2. Transcription factors: Proteins that promote transcription
   Bacterial uses sigma factors
   Eukaryotes use many general transcription factors which are a multi-protein complex
3. Regulatory elements (cis factors)
   Bacteria use few regulatory sequences
   Eukaryotes utilize many regulatory sequence, including enhancers and boundary elements

Question 3

Core promoter

Answer 3

Minimal set of sequence elements that are required for accurate transcription to occur

RNA poly II and the general transcription factors bind to the core promoter

Different genes have different core promoter elements!

Question 4

Core promoter sequences typically have:

Answer 4

Inr region → Determines the start site location

TATA box and BRE element → Pre-initiation complex forms

DCE/DPE (Downstream elements) → Other important roles in pre-initiation (Just discovered in 1996!)

Question 5

Formation of the Initiator Complex