The MarR-type repressor MhqR (YkvE) regulates multiple dioxygenases/glyoxalases and an azoreductase which confer resistance to 2-methylhydroquinone and catechol in Bacillus subtilis.
Catechol and 2-methylhydroquinone (2-MHQ) cause the induction of the thiol-specific stress response and four dioxygenases/glyoxalases in Bacillus subtilis. Using transcription factor arrays, the MarR-type regulator YkvE was identified as a repressor of the dioxygenase/glyoxalase-encoding mhqE gene. Transcriptional and proteome analyses of the DeltaykvE mutant revealed the upregulation of ykcA (mhqA), ydfNOP (mhqNOP), yodED (mhqED) and yvaB (azoR2) encoding multiple dioxygenases/glyoxalases, oxidoreductases and an azoreductase. Primer extension experiments identified sigma(A)-type promoter sequences upstream of mhqA, mhqNOP, mhqED and azoR2 from which transcription is elevated after thiol stress. DNase I footprinting analysis showed that YkvE protects a primary imperfect inverted repeat with the consensus sequence of tATCTcgaAtTCgAGATaaaa in the azoR2, mhqE and mhqN promoter regions. Analysis of mhqE-promoter-bgaB fusions confirmed the significance of YkvE binding to this operator in vivo. Adjacent secondary repeats were protected by YkvE in the azoR2 and mhqN promoter regions consistent with multiple DNA-protein binding complexes. DNA-binding activity of YkvE was not directly affected by thiol-reactive compounds in vitro. Mutational analyses showed that MhqA, MhqO and AzoR2 confer resistance to 2-MHQ. Moreover, the DeltaykvE mutant displayed a 2-MHQ and catechol resistant phenotype. YkvE was renamed as MhqR controlling a 2-MHQ and catechol-resistance regulon of B. subtilis.
Töwe
Stefanie
S
Institute for Microbiology, Ernst-Moritz-Arndt-University of Greifswald, F.-L.-Jahn-Str. 15, D-17487 Greifswald, Germany.
Leelakriangsak
Montira
M
Kobayashi
Kazuo
K
Van Duy
Nguyen
N
Hecker
Michael
M
Zuber
Peter
P
Antelmann
Haike
H
D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D001412:Bacillus subtilis / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D001665:Binding Sites / Q000235:genetics; D002396:Catechols / Q000378:metabolism / Q000494:pharmacology*; D018983:DNA Footprinting; D004269:DNA, Bacterial / Q000378:metabolism; D049308:Dioxygenases / Q000096:biosynthesis*; D024881:Drug Resistance, Bacterial / Q000502:physiology*; D024202:Electrophoretic Mobility Shift Assay; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D006873:Hydroquinones / Q000378:metabolism / Q000494:pharmacology*; D016254:Mutagenesis, Insertional; D009247:NADH, NADPH Oxidoreductases / Q000096:biosynthesis*; D009601:Nitroreductases; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020543:Proteome / Q000032:analysis; D012097:Repressor Proteins / Q000235:genetics / Q000502:physiology*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002396:Catechols; D004269:DNA, Bacterial; D006873:Hydroquinones; D020543:Proteome; D012097:Repressor Proteins; C062397:2-methyl-1,4-hydroquinone; D049308:Dioxygenases; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase; C034221:catechol