Identification of a novel bacteriocin regulatory system in Streptococcus mutans

Zhoujie Xie, Toshinori Okinaga, Guoqing Niu, Fengxia Qi, Justin Merritt

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

Recently, we described the function of an uncharacterized two-gene regulatory system consisting of a LytTR family transcription regulator and a putative membrane protein, which we referred to as the hdrRM operon. In this study, we determined that the HdrRM system controls the expression of an analogous uncharacterized regulatory system annotated as SMU.2080 and SMU.2081. Like hdrRM, the SMU.2080-2081 operon encodes a LytTR family transcription regulator and putative membrane protein, which we now refer to as BrsR and BrsM respectively. Examination of the regulatory mechanism of the BrsRM system suggests that BrsM serves to antagonize the function of the transcription regulator BrsR. Further analyses of the regulatory role of BrsR determined that it functions as a transcription activator for a variety of bacteriocins and bacteriocin-related genes. In vitro electromobility shift assays confirmed that BrsR binds to the promoter regions of several bacteriocin genes and requires the presence of a LytTR family consensus direct repeat in order to stably bind DNA. In addition, we identified a novel regulatory scheme in which both the HdrRM and BrsRM systems coregulate each other and ultimately determine whether bacteriocin production will inhibit competitor organisms or result in lethality to the producer.

Original languageEnglish (US)
Pages (from-to)1431-1447
Number of pages17
JournalMolecular Microbiology
Volume78
Issue number6
DOIs
Publication statusPublished - Dec 2010
Externally publishedYes

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ASJC Scopus subject areas

  • Molecular Biology
  • Microbiology

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