RRC ID 33555
Author Hirooka K, Kunikane S, Matsuoka H, Yoshida K, Kumamoto K, Tojo S, Fujita Y.
Title Dual regulation of the Bacillus subtilis regulon comprising the lmrAB and yxaGH operons and yxaF gene by two transcriptional repressors, LmrA and YxaF, in response to flavonoids.
Journal J. Bacteriol.
Abstract Bacillus subtilis LmrA is known to be a repressor that regulates the lmrAB and yxaGH operons; lmrB and yxaG encode a multidrug resistance pump and quercetin 2,3-dioxygenase, respectively. DNase I footprinting analysis revealed that LmrA and YxaF, which are paralogous to each other, bind specifically to almost the same cis sequences, LmrA/YxaF boxes, located in the promoter regions of the lmrAB operon, the yxaF gene, and the yxaGH operon for their repression and containing a consensus sequence of AWTATAtagaNYGgTCTA, where W, Y, and N stand for A or T, C or T, and any base, respectively (three-out-of-four match [in lowercase type]). Gel retardation analysis indicated that out of the eight flavonoids tested, quercetin, fisetin, and catechin are most inhibitory for LmrA to DNA binding, whereas quercetin, fisetin, tamarixetin, and galangin are most inhibitory for YxaF. Also, YxaF bound most tightly to the tandem LmrA/YxaF boxes in the yxaGH promoter region. The lacZ fusion experiments essentially supported the above-mentioned in vitro results, except that galangin did not activate the lmrAB and yxaGH promoters, probably due to its poor incorporation into cells. Thus, the LmrA/YxaF regulon presumably comprising the lmrAB operon, the yxaF gene, and the yxaGH operon is induced in response to certain flavonoids. The in vivo experiments to examine the regulation of the synthesis of the reporter beta-galactosidase and quercetin 2,3-dioxgenase as well as that of multidrug resistance suggested that LmrA represses the lmrAB and yxaGH operons but that YxaF represses yxaGH more preferentially.
Volume 189(14)
Pages 5170-82
Published 2007-7
DOI 10.1128/JB.00079-07
PII JB.00079-07
PMID 17483215
PMC PMC1951842
MeSH Amino Acid Sequence Bacillus subtilis / drug effects Bacillus subtilis / genetics* Bacillus subtilis / metabolism Bacterial Proteins / genetics* Bacterial Proteins / metabolism Base Sequence Catechin / chemistry Catechin / pharmacology DNA Footprinting Dioxygenases / genetics Dioxygenases / metabolism Disaccharides / chemistry Disaccharides / pharmacology Electrophoretic Mobility Shift Assay Flavonoids / chemistry Flavonoids / pharmacology* Gene Expression Regulation, Bacterial / drug effects Lincomycin / chemistry Lincomycin / pharmacology Molecular Sequence Data Molecular Structure Oligonucleotide Array Sequence Analysis Operon / genetics* Promoter Regions, Genetic / genetics Protein Binding / drug effects Quercetin / analogs & derivatives Quercetin / chemistry Quercetin / pharmacology Regulon / genetics* Repressor Proteins / genetics* Repressor Proteins / metabolism Sequence Homology, Amino Acid
IF 3.234
Times Cited 20
Prokaryotes B. subtilis MBS292 MBS293 MBS299 MBS300 MBS301 MBS302 MBS303 MBS304 MBS305 MBS308 MBS316