Membrane Topology and Structural Insights into the Peptide Pheromone Receptor ComD, A Quorum-Sensing Histidine Protein Kinase of Streptococcus mutans
| Autor: | Tianlei Liu, Geoffrey Tziolas, Gaofeng Dong, William Lin, Xiao-Lin Tian, Yung-Hua Li, Kayla Cyr |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Histidine Kinase Protein Conformation 030106 microbiology Peptide Biology Article Streptococcus mutans 03 medical and health sciences Protein structure Bacterial Proteins parasitic diseases Extracellular Point Mutation Receptor Protein kinase A chemistry.chemical_classification Multidisciplinary Cell Membrane Quorum Sensing Gene Expression Regulation Bacterial Transmembrane protein 3. Good health Quorum sensing Biochemistry chemistry Membrane topology |
| Zdroj: | Scientific Reports |
| ISSN: | 2045-2322 |
| Popis: | Quorum sensing activation by signal pheromone (CSP) in Streptococcus mutans depends on the membrane-associated receptor ComD, which senses the signal and triggers the signaling cascade for bacteriocin production and other cell density-dependent activities. However, the mechanism of the signal recognition via the ComD receptor in this species is nearly unexplored. Here, we show that the membrane domain of the ComD protein forms six transmembrane segments with three extracellular loops, loopA, loopB and loopC. By structural and functional analyses of these extracellular loops, we demonstrate that both loopC and loopB are required for CSP recognition, while loopA plays little role in CSP detection. A deletion or substitution mutation of four residues NVIP in loopC abolishes CSP recognition for quorum sensing activities. We conclude that both loopC and loopB are required for forming the receptor and residues NVIP of loopC are essential for CSP recognition and quorum sensing activation in S. mutans. |
| Databáze: | OpenAIRE |
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