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Bacterial enhancer-binding proteins: unlocking sigma54-dependent gene transcription
Mathieu Rappas1, Daniel Bose, Xiaodong Zhang
1Centre for Structural Biology, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK.
Current Opinion in Structural Biology
|December 13, 2006
Summary
Sigma54 (sigma54) factors are crucial for bacterial transcription, forming stable complexes with RNA polymerase (RNAP). Recent structural data reveal how enhancer-binding proteins use ATP hydrolysis to remodel these complexes, advancing our understanding of transcription activation.
Area of Science:
- Molecular Biology
- Biochemistry
- Structural Biology
Background:
- Bacterial transcription initiation requires sigma factors for RNA polymerase (RNAP) promoter specificity.
- The sigma54 (sigma54) factor forms a stable closed complex with RNAP and DNA, resisting spontaneous opening.
- Remodeling of the RNAP-sigma54-DNA closed complex is ATP-dependent, mediated by enhancer-binding proteins.
Purpose of the Study:
- To elucidate the mechanism of sigma54-dependent transcription activation.
- To provide structural insights into the function of bacterial enhancer-binding proteins.
- To understand how ATPase activity is converted into remodeling events.
Main Methods:
- Analysis of recent structural information on bacterial enhancer-binding proteins.
- Investigating nucleotide binding and hydrolysis mechanisms.
- Studying protein oligomerisation and its role in remodeling.
Main Results:
- Structural data provide a basis for understanding nucleotide binding and hydrolysis by enhancer-binding proteins.
- Insights into the oligomerisation of these proteins and their interaction with the RNAP-sigma54 complex.
- Demonstration of how ATPase activity drives the conversion of the closed complex to an open complex.
Conclusions:
- Recent structural studies offer unprecedented insights into the mechanism of sigma54-dependent transcription.
- The findings provide a structural framework for understanding the remodeling of the RNAP-sigma54-DNA closed complex.
- Advances are made towards a comprehensive understanding of the sigma54-dependent transcription activation pathway.
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