Regulation of the Bacillus subtilis divergent yetL and yetM genes by a transcriptional repressor, YetL, in response to flavonoids

J Bacteriol. 2009 Jun;191(11):3685-97. doi: 10.1128/JB.00202-09. Epub 2009 Mar 27.


DNA microarray analysis revealed that transcription of the Bacillus subtilis yetM gene encoding a putative flavin adenine dinucleotide-dependent monooxygenase was triggered by certain flavonoids during culture and was derepressed by disruption of the yetL gene in the opposite orientation situated immediately upstream of yetM, which encodes a putative MarR family transcriptional regulator. In vitro analyses, including DNase I footprinting and gel retardation analysis, indicated that YetL binds specifically to corresponding single sites in the divergent yetL and yetM promoter regions, with higher affinity to the yetM region; the former region overlaps the Shine-Dalgarno sequence of yetL, and the latter region contains a perfect 18-bp palindromic sequence (TAGTTAGGCGCCTAACTA). In vitro gel retardation and in vivo lacZ fusion analyses indicated that some flavonoids (kaempferol, apigenin, and luteolin) effectively inhibit YetL binding to the yetM cis sequence, but quercetin, galangin, and chrysin do not inhibit this binding, implying that the 4-hydroxyl group on the B-ring of the flavone structure is indispensable for this inhibition and that the coexistence of the 3-hydroxyl groups on the B- and C-rings does not allow antagonism of YetL.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apigenin / pharmacology
  • Bacillus subtilis / drug effects*
  • Bacillus subtilis / genetics*
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • DNA Footprinting
  • Flavonoids / pharmacology*
  • Gene Expression Regulation, Bacterial / drug effects*
  • Gene Expression Regulation, Bacterial / genetics
  • Kaempferols / pharmacology
  • Luteolin / pharmacology
  • Oligonucleotide Array Sequence Analysis
  • Promoter Regions, Genetic / genetics
  • Protein Binding


  • Bacterial Proteins
  • Flavonoids
  • Kaempferols
  • kaempferol
  • Apigenin
  • Luteolin