Atomic structure of the SAGA complex and it's interaction with TBP
Gabor Papai1,2,3,4, Alexandre Frechard1,2,3,4, Olga Kolesnikova1,2,3,4
1Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.
Comptes Rendus Biologies
|February 23, 2021
Summary
Researchers revealed the structure of the SAGA complex bound to TATA-box Binding Protein (TBP). This finding clarifies how TBP is delivered to gene promoters for transcription initiation.
Area of Science:
- Molecular Biology
- Structural Biology
- Biochemistry
Background:
- Eukaryotic gene transcription is regulated by protein complexes that guide RNA polymerase II.
- TATA-box Binding Protein (TBP) is crucial for identifying transcription start sites.
- The interaction and release mechanisms of TBP within transcription complexes like SAGA were previously unclear.
Purpose of the Study:
- To elucidate the structural basis of TBP interaction with the SAGA complex.
- To understand the mechanism of TBP delivery and release during transcription initiation.
Main Methods:
- Quasi-atomic modeling of the SAGA-TBP complex.
- Biochemical analysis of TBP-SAGA interactions.
Main Results:
- A detailed structural model of SAGA in complex with TBP was determined.
- A deformed histone-fold octamer within SAGA forms a specific TBP binding site.
- A mechanism involving TFIIA for TBP delivery and release, dependent on DNA affinity, was identified.
Conclusions:
- The study provides a structural understanding of TBP binding within the SAGA complex.
- A universal mechanism for TBP delivery to gene promoters during transcription initiation is proposed, applicable to both SAGA and TFIID complexes.
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