Determining the Roles of a Conserved α-Helix in a Global Virulence Regulator from Staphylococcus aureus
| Autor: | Subrata Sau, Keya Sau, Avisek Mahapa, Debabrata Sinha, Sukhendu Mandal |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Protein Conformation alpha-Helical Staphylococcus aureus 030106 microbiology Mutant Regulator Virulence Bioengineering medicine.disease_cause Biochemistry Analytical Chemistry 03 medical and health sciences chemistry.chemical_compound Bacterial Proteins medicine Bioorganic chemistry Gene Sequence Deletion Organic Chemistry Cell biology DNA-Binding Proteins 030104 developmental biology chemistry Helix Dimerization DNA |
| Zdroj: | The protein journal. 37(2) |
| ISSN: | 1875-8355 |
| Popis: | SarA, a pleiotropic transcription regulator, is encoded by Staphylococcus aureus, a pathogenic bacterium. The expression of many virulence and non-virulence genes in S. aureus is modulated by this regulator. Structural studies have shown it to be a winged-helix DNA-binding protein carrying two monomers. Each SarA monomer is composed of five α-helices (α1–α5), three β-strands (β1–β3) and multiple loops. The putative DNA binding region of SarA is constituted with α3, α4, β2, and β3, whereas, its dimerization seems to occur using α1, α2, and α5. Interestingly, many SarA-like proteins are dimeric and use three or more helices for their dimerization. To clearly understand the roles of helix α1 in the dimerization, we have constructed and purified a SarA mutant (Δα1) that lacks helix α1. Our in-depth studies with Δα1 indicate that the helix α1 is critical for preserving the structure, DNA binding activity and thermodynamic stability of SarA. However, the helix has little affected its dimerization ability. Possible reasons for such anomaly have been discussed at length. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink