The Solution Structures and Interaction of SinR and SinI: Elucidating the Mechanism of Action of the Master Regulator Switch for Biofilm Formation in Bacillus subtilis
| Autor: | Morgan E. Milton, Michael T. Santoro, Benjamin G. Bobay, Katherine H. Myers, Daniel B. Kearns, John Cavanagh, Sean D. Stowe, Andrew L. Olson, Richele J. Thompson, Erik A. Feldmann, G. Logan Draughn |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Protein Conformation
Repressor Bacillus subtilis Article 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Bacterial Proteins Tetramer Structural Biology Gene expression medicine Transcriptional regulation Amino Acid Sequence Molecular Biology 030304 developmental biology 0303 health sciences biology Biofilm Gene Expression Regulation Bacterial biology.organism_classification DNA-Binding Proteins Molecular Docking Simulation chemistry Mechanism of action Biofilms Mutation Biophysics medicine.symptom 030217 neurology & neurosurgery DNA Protein Binding |
| Zdroj: | J Mol Biol |
| ISSN: | 0022-2836 |
| Popis: | Bacteria have developed numerous protection strategies to ensure survival in harsh environments, with perhaps the most robust method being the formation of a protective biofilm. In biofilms, bacterial cells are embedded within a matrix that is composed of a complex mixture of polysaccharides, proteins, and DNA. The gram-positive bacterium Bacillus subtilis has become a model organism for studying regulatory networks directing biofilm formation. The phenotypic transition from a planktonic to biofilm state is regulated by the activity of the transcriptional repressor, SinR, and its inactivation by its primary antagonist, SinI. In this work, we present the first full-length structural model of tetrameric SinR using a hybrid approach combining high-resolution solution nuclear magnetic resonance (NMR), chemical cross-linking, mass spectrometry, and molecular docking. We also present the solution NMR structure of the antagonist SinI dimer and probe the mechanism behind the SinR-SinI interaction using a combination of biochemical and biophysical techniques. As a result of these findings, we propose that SinI utilizes a residue replacement mechanism to block SinR multimerization, resulting in diminished DNA binding and concomitant decreased repressor activity. Finally, we provide an evidence-based mechanism that confirms how disruption of the SinR tetramer by SinI regulates gene expression. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect