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DNA-affinity-purified Chip (DAP-chip) Method to Determine Gene Targets for Bacterial Two component Regulatory Systems
Published on: July 21, 2014
A two-subunit bacterial sigma-factor activates transcription in Bacillus subtilis
Shawn R MacLellan1, Veronica Guariglia-Oropeza, Ahmed Gaballa
1Department of Microbiology, Cornell University, 370 Wing Hall, Ithaca, NY 14853-8101, USA.
Summary
The sigma-like factor YvrI and coregulator YvrHa act as a two-subunit bacterial sigma-factor in Bacillus subtilis. They independently contribute to RNA polymerase binding and promoter recognition, enabling transcription activation.
Area of Science:
- Molecular Biology
- Microbial Genetics
- Transcription Regulation
Background:
- Bacillus subtilis utilizes sigma-like factors and coregulators to control gene transcription.
- Sigma factors are essential for bacterial transcription initiation by directing RNA polymerase to specific promoter sequences.
Purpose of the Study:
- To elucidate the distinct roles of YvrI and YvrHa in transcription activation.
- To characterize the interaction between YvrI, YvrHa, and RNA polymerase.
Main Methods:
- Protein-protein interaction studies
- Analysis of holoenzyme-promoter DNA complex formation
- Investigating DNA melting and open complex stabilization
Main Results:
- YvrI binds RNA polymerase (RNAP) via region 4, recognizing the -35 promoter element but not initiating DNA melting.
- YvrHa binds RNAP beta'-subunit via a sigma-region 2-like motif, stabilizing the open complex at the -10 promoter element.
- YvrHa and YvrI interact, with YvrHa stabilizing YvrI's function.
Conclusions:
- YvrI and YvrHa function as an unusual two-subunit bacterial sigma-factor system.
- This system demonstrates a novel mechanism for promoter recognition and transcription initiation in Bacillus subtilis.
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