TherfaHgene, which affects lipopolysaccharide synthesis inSalmonella entericaserovar Typhi, is differentially expressed during the bacterial growth phase
| Autor: | Soledad Saldı́as, Inés Contreras, Gonzalo M. Rojas, Mercedes Zaldívar, Mauricio Bittner |
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| Rok vydání: | 2001 |
| Předmět: |
Lipopolysaccharides
Transcription Genetic Mutant medicine.disease_cause Salmonella typhi Microbiology Plasmid Genetics medicine Cloning Molecular Site-directed mutagenesis Molecular Biology Escherichia coli Gene Regulation of gene expression biology Reverse Transcriptase Polymerase Chain Reaction Escherichia coli Proteins Genetic Complementation Test Gene Expression Regulation Bacterial Peptide Elongation Factors biology.organism_classification Enterobacteriaceae Mutagenesis Site-Directed Trans-Activators |
| Zdroj: | FEMS MICROBIOLOGY LETTERS Artículos CONICYT CONICYT Chile instacron:CONICYT |
| ISSN: | 1574-6968 0378-1097 |
| DOI: | 10.1111/j.1574-6968.2001.tb10874.x |
| Popis: | We have cloned and sequenced the rfaH gene from Salmonella enterica serovar Typhi strain Ty2. The gene showed a high degree of similarity to the rfaH genes from Escherichia coli K-12 and S. enterica serovar Typhimurium. A rfaH mutant was constructed by site-directed mutagenesis. This mutant produced a rough lipopolysaccharide (LPS), with an incomplete core region. The defect in LPS expression that results from the rfaH mutation was corrected by a plasmid carrying the intact gene. The plasmid-borne rfaH gene also restored normal LPS synthesis in a rfaH mutant of E. coli. Reverse transcription-polymerase chain reaction analyses were performed to determine the effects of various environmental conditions on the expression of rfaH. The transcription of rfaH showed a growth-phase-dependent regulation, with maximal expression at the late exponential phase. Other environmental conditions, such as temperature or medium osmolarity, did not affect transcription of rfaH. |
| Databáze: | OpenAIRE |
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