Unique stress response to the lactoperoxidase-thiocyanate enzyme system in Escherichia coli.
Using a differential fluorescence induction approach, we screened a promoter trap library constructed in a vector with a promoterless gfp gene for Escherichia coli MG1655 promoters that are induced upon challenge with the antimicrobial lactoperoxidase-thiocyanate enzyme system. None of the thirteen identified lactoperoxidase-inducible open reading frames was inducible by H(2)O(2) or by the superoxide generator plumbagin. However, analysis of specific promoters of known stress genes showed some of these, including recA, dnaK and sodA, to be inducible by the lactoperoxidase-thiocyanate enzyme system. The results show that the lactoperoxidase-thiocyanate enzyme system elicits a distinct stress response different from but partly overlapping other oxidative stress responses. Several of the induced genes or pathways may be involved in bacterial defense against the toxic effects of the lactoperoxidase-thiocyanate enzyme system.
Sermon
Jan
J
Laboratory of Food Microbiology, Katholieke Universiteit Leuven, Kasteelpark Arenberg 22, 3001 Leuven (Heverlee), Belgium.
Vanoirbeek
Kristof
K
De Spiegeleer
Philipp
P
Van Houdt
Rob
R
Aertsen
Abram
A
Michiels
Chris W
CW
D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D005453:Fluorescence; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007784:Lactoperoxidase / Q000378:metabolism*; D018384:Oxidative Stress; D011401:Promoter Regions, Genetic; D013481:Superoxides / Q000494:pharmacology; D013861:Thiocyanates / Q000378:metabolism*
D029968:Escherichia coli Proteins; D013861:Thiocyanates; D013481:Superoxides; D006861:Hydrogen Peroxide; D007784:Lactoperoxidase; C031760:thiocyanate