Identification of a hypochlorite-specific transcription factor from Escherichia coli.
Hypochlorite is a powerful oxidant produced by neutrophils to kill invading microorganisms. Despite this important physiological role of HOCl in fighting bacterial infections, no hypochlorite-specific stress response has been identified yet. Here, we identified a hypochlorite-responsive transcription factor, YjiE, which is conserved in proteobacteria and eukaryotes. YjiE forms unusual dodecameric ring-like structures in vitro that undergo large DNA-induced conformational changes to form dimers and tetramers as shown by transmission electron microscopy and analytical ultracentrifugation. Such smaller oligomers are predominant in hypochlorite-stressed cells and are the active species as shown by fluorescence anisotropy and analytical ultracentrifugation. YjiE regulates a large number of genes upon hypochlorite stress. Among them are genes involved in cysteine, methionine biosynthesis, and sulfur metabolism (up-regulated) and genes involved in iron acquisition and homeostasis (down-regulated), thus supposedly replenishing oxidized metabolites and decreasing the hypochlorite-mediated amplification of intracellular reactive oxygen species. As a result, YjiE specifically confers hypochlorite resistance to E. coli cells. Thus, to our knowledge, YjiE is the first described hypochlorite-specific transcription factor.
Section of Biotechnology, Department of Chemistry, Center for Integrated Protein Science Munich, Technische Universität München, 85747 Garching, Germany.
Katharina M
KM
Gebendorfer
Adrian
A
Drazic
Yan
Y
Le
Jasmin
J
Gundlach
Alexander
A
Bepperling
Andreas
A
Kastenmüller
Kristina A
KA
Ganzinger
Nathalie
N
Braun
Titus M
TM
Franzmann
Jeannette
J
Winter
D000595:Amino Acid Sequence; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004202:Disinfectants / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D006997:Hypochlorous Acid / Q000494:pharmacology*; D008969:Molecular Sequence Data; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D004202:Disinfectants; D029968:Escherichia coli Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D006997:Hypochlorous Acid; C117348:KptA protein, E coli; D017853:Phosphotransferases (Alcohol Group Acceptor)