TY - JOUR
T1 - Differential activities of the SoxR protein of Escherichia coli
T2 - SoxS is not required for gene activation under iron deprivation
AU - Fuentes, Ana M.
AU - Díaz-Mejía, J. Javier
AU - Maldonado-Rodríguez, Rogelio
AU - Amábile-Cuevas, Carlos F.
PY - 2001/7/24
Y1 - 2001/7/24
N2 - 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.
AB - 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.
KW - Escherichia coli
KW - Stress response
KW - soxRS
UR - http://www.scopus.com/inward/record.url?scp=0035943115&partnerID=8YFLogxK
U2 - 10.1016/S0378-1097(01)00283-X
DO - 10.1016/S0378-1097(01)00283-X
M3 - Artículo
SN - 0378-1097
VL - 201
SP - 271
EP - 275
JO - FEMS Microbiology Letters
JF - FEMS Microbiology Letters
IS - 2
ER -