ENTEROBACTIN PROTECTS Escherichia coli FROM THE ROS-MEDIATED TOXIC EFFECTS OF COPPER

PERALTA D; ADLER, C.; CORBALAN , N.; PAZ GARCÍA, EC; VINCENT ,P A.; POMARES, M.F.

Mar del Plata

Congreso; 51 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2015

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Siderophores are metal-chelating agents produced by bacteria under Fe-limiting conditions. Its primary function is tochelate the ferric iron and therefore make it available. Recent reports indicate that siderophores have wider and morecomplex functions than those known. We previously reported the requirement of enterobactin, a catechol siderophoreproduced by E. coli, for colony development in minimal media (M9) and proposed a new function as an intracellularoxidative stress protector. Now, we analyzed the role of enterobactin in copper toxicity. We showed that the lack ofenterobactin increased copper cell sensitivity. Addition of enterobactin to the media protected cells; on the otherhand, supplementation with iron didn?t impact on the sensitivity to copper. Besides, we observed that enterobactinmust to be internalized and hydrolyzed to confer a full protection against copper damage. Also, entE expressionincreased in cells growing in M9 and LB supplemented with copper. Finally, we found that the addition of copper toentE mutant increased levels of reactive oxygen species, which were lowered in the presence of exogenousenterobactin. Results suggest that the copper toxicity in enterobactin deficient mutants could be due to the oxidativestress generated by this metal and support our hypothesis implying cathecols siderophores in an oxidative stressprotection function.