Analysis of Streptococcus salivarius urease expression using continuous chemostat culture
نویسندگان
چکیده
منابع مشابه
Dual functions of Streptococcus salivarius urease.
A urease-deficient derivative of Streptococcus salivarius 57.I was constructed by allelic exchange at the ureC locus. The wild-type strain was protected against acid killing through hydrolysis of physiologically relevant concentrations of urea, whereas the mutant was not. Also, S. salivarius could use urea as a source of nitrogen for growth exclusively through a urease-dependent pathway.
متن کاملStreptococcus salivarius urease: genetic and biochemical characterization and expression in a dental plaque streptococcus.
The hydrolysis of urea by urease enzyme of oral bacteria is believed to have a major impact on oral microbial ecology and to be intimately involved in oral health and diseases. To begin to understand the biochemistry and genetics of oral ureolysis, a study of the urease of Streptococcus salivarius, a highly ureolytic organism which is present in large numbers on the soft tissues of the oral cav...
متن کاملTranscriptional regulation of the Streptococcus salivarius 57.I urease operon.
The Streptococcus salivarius 57.I ure cluster was organized as an operon, beginning with ureI, followed by ureABC (structural genes) and ureEFGD (accessory genes). Northern analyses revealed transcripts encompassing structural genes and transcripts containing the entire operon. A sigma70-like promoter could be mapped 5' to ureI (PureI) by primer extension analysis. The intensity of the signal i...
متن کاملThe pH-dependent expression of the urease operon in Streptococcus salivarius is mediated by CodY.
Urease gene expression in Streptococcus salivarius 57.I, a strain of one of the major alkali producers in the mouth, is induced by acidic pH and excess amounts of carbohydrate. Expression is controlled primarily at the transcriptional level from a promoter, pureI. Recent sequencing analysis revealed a CodY box located 2 bases 5' to the -35 element of pureI. Using continuous chemostat culture, t...
متن کاملcadDX operon of Streptococcus salivarius 57.I.
A CadDX system that confers resistance to Cd(2+) and Zn(2+) was identified in Streptococcus salivarius 57.I. Unlike with other CadDX systems, the expression of the cad promoter was negatively regulated by CadX, and the repression was inducible by Cd(2+) and Zn(2+), similar to what was found for CadCA systems. The lower G+C content of the S. salivarius cadDX genes suggests acquisition by horizon...
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ژورنال
عنوان ژورنال: FEMS Microbiology Letters
سال: 1996
ISSN: 0378-1097
DOI: 10.1016/0378-1097(95)00454-8