Expression of the yggE gene protects Escherichia coli from potassium tellurite-generated oxidative stress

Abstract

Potassium tellurite is highly toxic to most forms of life and specific bacterial tellurite defense mechanisms are not fully understood to date. Recent evidence suggests that tellurite would exert its toxic effects, at least in part, through the generation of superoxide anion that occurs concomitantly with intracellular tellurite (Te(4+)) reduction to elemental tellurium (Te(o)). In this work the putative antioxidant role of YggE from Escherichia coli, a highly conserved protein in several bacterial species and whose function is still a matter of speculation, was studied. When exposed to tellurite, E. coli lacking yggE exhibited increased activity of superoxide dismutase and fumarase C, augmented levels of reactive oxygen species and high concentration of carbonyl groups in proteins. Upon genetic complementation with the homologous yggE gene these values were restored to those observed in the parental, isogenic, wild type strain, suggesting a direct participation of YggE in E. coli tolerance to tellurite.

Morphological and proteomic analysis of biofilms from the Antarctic archaeon, Halorubrum lacusprofundi

“…The increased abundance of a YggE homolog (Hlac_2298) in biofilms was an indicator of oxidative stress as it is homologous to a periplasmic protein from E. coli that is inferred to protect cells against oxidative stress5354. Intracellularly, cysteine serves as a reductant that drives the Fenton reaction, which generates hydroxyl radicals from iron (II) and hydrogen peroxide, thereby causing damage to DNA55.…”

Enhancing E. coli Tolerance towards Oxidative Stress via Engineering Its Global Regulator cAMP Receptor Protein (CRP)

“…Luria Bertinii (LB) medium (Bacto tryptone (Oxoid) 10 g/l, Yeast extract (Merck) 5 g/l, Sodium Chloride (Merck) 10 g/l) was routinely used for bacterial culture since it has been a popular medium choice for E. coli growth under oxidative stress [36], [41]. SOC medium (Yeast extract 5 g/l, Tryptone 20 g/l, NaCl 10 mM, KCl 2.5 mM, MgCl 2 10 mM, MgSO 4 10 mM, Glucose 20 mM) was used for cultivation of transformed cells.…”

“…In addition, oxidative stress in E. coli also induces chaperone such as Hsp33 to protect plenty of cellular proteins from stress generated shock [34]. Traditional approaches have been adopted to construct mutant E. coli strain via spontaneous adaptation [35] and cloning of exogenous antioxidant genes [36]. Earlier reports suggested that OxyR and RpoS, two major regulators of oxidative stress response in E. coli , were either directly or indirectly regulated by CRP [37].…”

The ActP acetate transporter acts prior to the PitA phosphate carrier in tellurite uptake by Escherichia coli

“…Along the same line, other bacteria detoxify tellurite by producing alkylated tellurium derivatives such as dimethyl tellurium and dimethyl ditelluride (Chasteen and Bentley, 2003;Araya et al, 2004;Chasteen et al, 2009 Currently, bacterial tellurite resistance is considered a multifactor response that involves, directly or indirectly, substrates and/or products of a number of metabolic pathways (Acuña et al, 2009;Castro et al, 2008Castro et al, , 2009Valdivia-González et al, 2012). Given that tellurite exerts toxic effects only once it is inside the cell, it is mandatory to unveil the mechanism by which tellurite is transported from the extracellular space.…”