Open AccessDifferential activities of the SoxR protein of Escherichia coli : SoxS is not required for gene activation under iron deprivation
Author(s) -
Fuentes Ana M.,
Dı́azMejı́a J.Javier,
MaldonadoRodrı́guez Rogelio,
AmábileCuevas Carlos F.
Publication year - 2001
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2001.tb10768.x
Subject(s) - escherichia coli , gene , escherichia coli proteins , chemistry , microbiology and biotechnology , biology , genetics , biochemistry
When Escherichia coli cells are under superoxide stress, proteins SoxR and SoxS, acting sequentially, control the expression of a set of repair and defense genes. One of these genes, fumC , encoding fumarase C, was reported to be also activated by iron deprivation in a soxRS ‐dependent manner. However, the same condition failed to induce the expression of a soxS′::lacZ fusion. The expression of acnA (aconitase A) is also activated by SoxR alone when under iron deprivation, but not of sodA (Mn‐superoxide‐dismutase). SoxR completely inhibited the migration of a DNA fragment containing the promoter region of fumC , in gel‐shift experiments. SoxR might bind to a different region than SoxS within the fumC promoter, or an unknown intermediate other than SoxS might be acting. It is possible that the regulatory role of SoxR is more complex than previously considered.