Premium
Regulation of S treptococcus mutans PTS Bio by the transcriptional repressor NigR
Author(s) -
Vujanac M.,
Iyer V.S.,
Sengupta M.,
Ajdic D.
Publication year - 2015
Publication title -
molecular oral microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 77
eISSN - 2041-1014
pISSN - 2041-1006
DOI - 10.1111/omi.12093
Subject(s) - streptococcus mutans , repressor , operon , pep group translocation , transcriptional regulation , transcription (linguistics) , lac repressor , biology , nucleotide , biochemistry , chemistry , transcription factor , escherichia coli , gene , genetics , bacteria , linguistics , philosophy
Summary Streptococcus mutans is implicated in human dental caries, and the carbohydrate metabolism of this organism plays an important role in the formation of this disease. Carbohydrate transport and metabolism are essential for the survival of S. mutans in the oral cavity. It is known that a unique phosphoenolpyruvate‐sugar phosphotransferase system PTS B io of S. mutans UA 159 is expressed in sucrose‐grown biofilms ( Mol Oral Microbiol 28: 2013; 114). In this study we analyzed the transcriptional regulation of the operon ( O B io ) encoding the PTS B io and showed that it was repressed by NigR, a LacI‐like transcriptional regulator. Using electro‐mobility shift assay, we described two operators to which NigR bound with different affinities. We also identified the transcriptional start site and showed that one of the operators overlaps with the promoter and presumably represses initiation of transcription. Mutational analyses revealed the key nucleotides in the operators required for high‐affinity binding of NigR. PTS B io is expressed in S. mutans biofilms so understanding its regulation may provide improved strategies for caries treatment and prevention.