Accession Number : ADA471918


Title :   Octanoyl-Homoserine Lactone Is the Cognate Signal for Burkholderia mallei BmaR1-BmaI1 Quorum Sensing


Descriptive Note : Journal article


Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF MICROBIOLOGY


Personal Author(s) : Duerkop, Breck A ; Ulrich, Ricky L ; Greenberg, E P


Full Text : http://www.dtic.mil/dtic/tr/fulltext/u2/a471918.pdf


Report Date : Jul 2007


Pagination or Media Count : 8


Abstract : Acyl-homoserine lactones (HSLs) serve as quorum-sensing signals for many Proteobacteria. Members of the LuxI family of signal generators catalyze the production of acyl-HSLs, which bind to a cognate receptor in the LuxR family of transcription factors. The obligate animal pathogen Burkholderia mallei produces several acyl-HSLs, and the B. mallei genome has four luxR and two luxI homologs, each of which has been established as a virulence factor. To begin to delineate the relevant acyl-HSL signals for B. mallei LuxR homologs, we analyzed the BmaR1-BmaI1 system. A comparison of acyl-HSL profiles from B. mallei ATCC 23344 and a B. mallei bmaI1 mutant indicates that octanoyl-HSL synthesis is BmaI1 dependent. Furthermore, octanoyl-HSL is the predominant acyl-HSL produced by BmaI1 in recombinant Escherichia coli. The synthesis of soluble BmaR1 in recombinant E. coli requires octanoyl-HSL or decanoyl-HSL. Insoluble aggregates of BmaR1 are produced in the presence of other acyl-HSLs and in the absence of acyl-HSLs. The bmaI1 promoter is activated by BmaR1 and octanoyl-HSL, and a 20-bp inverted repeat in the bmaI1 promoter is required for bmaI1 activation. Purified BmaR1 binds to this promoter region. These findings implicate octanoyl-HSL as the signal for BmaR1-BmaI1 quorum sensing and show that octanoyl-HSL and BmaR1 activate bmaI1 transcription.


Descriptors :   *ACTINOBACILLUS MALLEI , *LACTONES , REPRINTS , MODELS , GENOME , EXPERIMENTAL DESIGN , VIRULENCE


Subject Categories : Genetic Engineering and Molecular Biology
      Microbiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE