Genetic analysis of the functions and interactions of components of the LevQRST signal transduction complex of Streptococcus mutans.

Transcription of the genes for a fructan hydrolase (fruA) and a fructose/mannose sugar:phosphotransferase permease (levDEFG) in Streptococcus mutans is activated by a four-component regulatory system consisting of a histidine kinase (LevS), a response regulator (LevR) and two carbohydrate-binding pr...

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Main Authors: Lin Zeng, Satarupa Das, Robert A Burne
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2011-02-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3043104?pdf=render
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spelling doaj-6263cb697bcf49b49dd7c4ddde64c7c02020-11-25T02:46:54ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-02-0162e1733510.1371/journal.pone.0017335Genetic analysis of the functions and interactions of components of the LevQRST signal transduction complex of Streptococcus mutans.Lin ZengSatarupa DasRobert A BurneTranscription of the genes for a fructan hydrolase (fruA) and a fructose/mannose sugar:phosphotransferase permease (levDEFG) in Streptococcus mutans is activated by a four-component regulatory system consisting of a histidine kinase (LevS), a response regulator (LevR) and two carbohydrate-binding proteins (LevQT). The expression of the fruA and levD operons was at baseline in a levQ mutant and substantially decreased in a levT null mutant, with lower expression with the cognate inducers fructose or mannose, but slightly higher expression in glucose or galactose. A strain expressing levQ with two point mutations (E170A/F292S) did not require inducers to activate gene expression and displayed altered levD expression when growing on various carbohydrates, including cellobiose. Linker-scanning (LS) mutagenesis was used to generate three libraries of mutants of levQ, levS and levT that displayed various levels of altered substrate specificity and of fruA/levD gene expression. The data support that LevQ and LevT are intimately involved in the sensing of carbohydrate signals, and that LevQ appears to be required for the integrity of the signal transduction complex, apparently by interacting with the sensor kinase LevS.http://europepmc.org/articles/PMC3043104?pdf=render
collection DOAJ
language English
format Article
sources DOAJ
author Lin Zeng
Satarupa Das
Robert A Burne
spellingShingle Lin Zeng
Satarupa Das
Robert A Burne
Genetic analysis of the functions and interactions of components of the LevQRST signal transduction complex of Streptococcus mutans.
PLoS ONE
author_facet Lin Zeng
Satarupa Das
Robert A Burne
author_sort Lin Zeng
title Genetic analysis of the functions and interactions of components of the LevQRST signal transduction complex of Streptococcus mutans.
title_short Genetic analysis of the functions and interactions of components of the LevQRST signal transduction complex of Streptococcus mutans.
title_full Genetic analysis of the functions and interactions of components of the LevQRST signal transduction complex of Streptococcus mutans.
title_fullStr Genetic analysis of the functions and interactions of components of the LevQRST signal transduction complex of Streptococcus mutans.
title_full_unstemmed Genetic analysis of the functions and interactions of components of the LevQRST signal transduction complex of Streptococcus mutans.
title_sort genetic analysis of the functions and interactions of components of the levqrst signal transduction complex of streptococcus mutans.
publisher Public Library of Science (PLoS)
series PLoS ONE
issn 1932-6203
publishDate 2011-02-01
description Transcription of the genes for a fructan hydrolase (fruA) and a fructose/mannose sugar:phosphotransferase permease (levDEFG) in Streptococcus mutans is activated by a four-component regulatory system consisting of a histidine kinase (LevS), a response regulator (LevR) and two carbohydrate-binding proteins (LevQT). The expression of the fruA and levD operons was at baseline in a levQ mutant and substantially decreased in a levT null mutant, with lower expression with the cognate inducers fructose or mannose, but slightly higher expression in glucose or galactose. A strain expressing levQ with two point mutations (E170A/F292S) did not require inducers to activate gene expression and displayed altered levD expression when growing on various carbohydrates, including cellobiose. Linker-scanning (LS) mutagenesis was used to generate three libraries of mutants of levQ, levS and levT that displayed various levels of altered substrate specificity and of fruA/levD gene expression. The data support that LevQ and LevT are intimately involved in the sensing of carbohydrate signals, and that LevQ appears to be required for the integrity of the signal transduction complex, apparently by interacting with the sensor kinase LevS.
url http://europepmc.org/articles/PMC3043104?pdf=render
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AT robertaburne geneticanalysisofthefunctionsandinteractionsofcomponentsofthelevqrstsignaltransductioncomplexofstreptococcusmutans
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