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Updated: Jun 28, 2026
11:42
Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
A full-length group 1 bacterial sigma factor adopts a compact structure incompatible with DNA binding.
Edmund C Schwartz1, Alexander Shekhtman, Kaushik Dutta
1Laboratory of Synthetic Protein Chemistry, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
Chemistry & Biology
|October 23, 2008
Summary
Group 1 sigma factors regulate bacterial transcription. The sigma1.1 domain autoinhibits DNA binding by stabilizing a compact sigmaA factor structure, preventing RNA polymerase recruitment.
Area of Science:
- Bacterial transcription regulation
- Protein structure and function
Background:
- Sigma factors are essential for bacterial transcription initiation.
- Group 1 sigma factors control most transcription during log-phase growth.
- These factors are autoregulated by an N-terminal sigma1.1 domain.
Purpose of the Study:
- To determine the solution structure of Thermotoga maritima sigmaA sigma1.1.
- To investigate the interaction between sigma1.1 and promoter recognition domains of sigmaA.
Main Methods:
- Solution structure determination
- Chemical crosslinking strategies
Main Results:
- The solution structure of Thermotoga maritima sigmaA sigma1.1 was determined.
- Sigma1.1 was found to be in close proximity to sigmaA's promoter recognition domains.
- Evidence suggests sigma1.1 stabilizes a compact, DNA-binding-incompetent conformation.
Conclusions:
- Sigma1.1 autoinhibition mechanism proposed for sigmaA.
- This mechanism involves stabilizing a compact protein structure that prevents DNA binding.
- Understanding this autoregulation is key to bacterial transcription control.
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