The motifs commonly found in the core promoter of eukaryotic protein coding genes are:
A. TATA and Pribnow box
B. Motif ten element and TATA
C. BRE and Kozak consensus sequence
D. TRE and TATA

 

 

Introduction: Core Promoter Elements in Eukaryotic Genes

In molecular biology, the core promoter is a critical region of DNA located near the transcription start site of protein-coding genes. It serves as the binding site for the transcription machinery and helps initiate transcription effectively.

Understanding which motifs are found in these core promoter regions is essential for interpreting gene regulation and expression.

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✅ Correct Answer: B. Motif Ten Element and TATA

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Key Motifs in Eukaryotic Core Promoters

1. TATA Box

• Found approximately 25-30 base pairs upstream of the transcription start site.
• Recognized by the TATA-binding protein (TBP), a subunit of transcription factor TFIID.
• Helps position RNA polymerase II for accurate transcription initiation.

2. Motif Ten Element (MTE)

• Found downstream of the transcription start site (around +18 to +27).
• Functions in conjunction with other promoter elements like the Initiator (Inr).
• Plays a key role in basal transcription, especially when the TATA box is absent.

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Eliminating the Incorrect Options

A. TATA and Pribnow box – ❌ Incorrect

• The Pribnow box is found in prokaryotes, not eukaryotes.

C. BRE and Kozak consensus sequence – ❌ Incorrect

• BRE (TFIIB recognition element) is part of the core promoter but not as commonly found as TATA/MTE.
• Kozak sequence is associated with translation, not transcription.

D. TRE and TATA – ❌ Incorrect

• TRE (TPA-responsive element) is found in enhancer regions, not in core promoters.

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Summary

• The core promoter of eukaryotic protein-coding genes often contains the TATA box and the Motif Ten Element (MTE).
• These motifs ensure precise and regulated transcription initiation by recruiting the necessary transcription factors.