Abstract
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.
Original language | English |
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Pages (from-to) | 123-128 |
Number of pages | 6 |
Journal | FEMS Microbiology Letters |
Volume | 204 |
Issue number | 1 |
DOIs | |
Publication status | Published - 16 Oct 2001 |
Keywords
- Lipopolysaccharide
- RfaH
- Salmonella typhi
ASJC Scopus subject areas
- Microbiology
- Molecular Biology
- Genetics