Characterization of a two-component system in Streptococcus pyogenes which is involved in regulation of hyaluronic acid production
| Autor: | Ivo van de Rijn, Brian W. Bernish |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Transposable element
DNA Bacterial Operon Streptococcus pyogenes Mutant Molecular Sequence Data DNA Footprinting Biology medicine.disease_cause Biochemistry Binding Competitive medicine Hyaluronic Acid Promoter Regions Genetic Molecular Biology Alleles Base Sequence Promoter Cell Biology Molecular biology Two-component regulatory system Organophosphates Repressor Proteins Response regulator Genes Bacterial Mutagenesis DNA Transposable Elements Transposon mutagenesis |
| Zdroj: | The Journal of biological chemistry. 274(8) |
| ISSN: | 0021-9258 |
| Popis: | Hyaluronic acid production by group A streptococci is regulated by transcriptional control. In this study, transposon mutagenesis of an unencapsulated strain yielded an encapsulated mutant. Two genes homologous to sensors and response regulators of bacterial two-component systems were identified downstream of the transposon insertion. Inactivation of the putative sensor gene, csrS, in three different unencapsulated strains yielded encapsulated mutant strains. Electrophoretic mobility shift assays determined factor(s) in a cytoplasmic extract of an unencapsulated group A streptococcal strain was binding to a double-stranded DNA fragment derived from the has operon promoter. In contrast, similarly prepared cytoplasmic extracts from a csrS deletion mutant did not shift the fragment. The putative response regulator, CsrR, was partially purified and was shown to bind the has operon promoter fragment. The affinity and specificity of CsrR for the fragment were increased significantly after incubation with acetyl phosphate. DNase I footprinting determined that the acetyl phosphate-treated CsrR was binding to key sequences in the promoter and the coding region of hasA. Therefore, a two-component system is repressing the production of hyaluronic acid in group A streptococci using a phosphorylation-dependent binding interaction between the response regulator CsrR and the promoter region of the has operon. |
| Databáze: | OpenAIRE |
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