Methionine-rich domains emerge as facilitators of copper recruitment in detoxification systems.

Copper homeostasis mechanisms are critical for bacterial resistance to copper-induced stress. The multicopper oxidase copper efflux oxidase (CueO) is part of the copper detoxification system in aerobic conditions. CueO contains a methionine-rich (Met-rich) domain believed to interact with copper, but its exact function and the importance of related copper-binding sites remain unclear.

Typhimurium uses the Cpx stress response to detect -chlorotaurine and promote the repair of oxidized proteins.

The cell envelope of gram-negative bacteria constitutes the first protective barrier between a cell and its environment. During host infection, the bacterial envelope is subjected to several stresses, including those induced by reactive oxygen species (ROS) and reactive chlorine species (RCS) produced by immune cells. Among RCS, chlorotaurine (ChT), which results from the reaction between hypochlorous acid and taurine, is a powerful and less diffusible oxidant.

Periplasmic oxidized-protein repair during copper stress in E. coli: A focus on the metallochaperone CusF.

Methionine residues are particularly sensitive to oxidation by reactive oxygen or chlorine species (ROS/RCS), leading to the appearance of methionine sulfoxide in proteins. This post-translational oxidation can be reversed by omnipresent protein repair pathways involving methionine sulfoxide reductases (Msr). In the periplasm of Escherichia coli, the enzymatic system MsrPQ, whose expression is triggered by the RCS, controls the redox status of methionine residues.

HprSR Is a Reactive Chlorine Species-Sensing, Two-Component System in Escherichia coli.

Two-component systems (TCS) are signaling pathways that allow bacterial cells to sense, respond to, and adapt to fluctuating environments. Among the classical TCS of Escherichia coli, HprSR has recently been shown to be involved in the regulation of , which encodes the periplasmic methionine sulfoxide reductase system. In this study, we demonstrated that hypochlorous acid (HOCl) induces the expression of in an HprSR-dependent manner, whereas HO, NO, and paraquat (a superoxide generator) do not.

Methionine Redox Homeostasis in Protein Quality Control.

Bacteria live in different environments and are subject to a wide variety of fluctuating conditions. During evolution, they acquired sophisticated systems dedicated to maintaining protein structure and function, especially during oxidative stress. Under such conditions, methionine residues are converted into methionine sulfoxide (Met-O) which can alter protein function.

The Esterase PfeE, the Achilles' Heel in the Battle for Iron between and .

Bacteria access iron, a key nutrient, by producing siderophores or using siderophores produced by other microorganisms. The pathogen produces two siderophores but is also able to pirate enterobactin (ENT), the siderophore produced by . ENT-Fe complexes are imported across the outer membrane of by the two outer membrane transporters PfeA and PirA.

Bacterial Genetic Approach to the Study of Reactive Oxygen Species Production in During Infection.

Over the last decade, an increasing number of reports presented larvae as an important model to study host-pathogen interactions. Coherently, increasing information became available about molecular mechanisms used by this host to cope with microbial infections but few of them dealt with oxidative stress. In this work, we addressed the role of reactive oxygen species (ROS) produced by the immune system of to resist against , an intracellular pathogen responsible for a wide range of infections.

Characterisation of the periplasmic methionine sulfoxide reductase (MsrP) from Salmonella Typhimurium.

The oxidation of free methionine (Met) and Met residues inside proteins leads to the formation of methionine sulfoxide (Met-O). The reduction of Met-O to Met is catalysed by a ubiquitous enzyme family: the methionine sulfoxide reductases (Msr). The importance of Msr systems in bacterial physiology and virulence has been reported in many species.

Author Correction: The MFS efflux pump EmrKY contributes to the survival of Shigella within macrophages.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

[The greater wax moth, Galleria mellonella to study host-pathogen interactions].

The massive use of antibiotics in health and agriculture has led to the emergence of pathogenic microorganisms resistant to frequently used treatments. In 2017, the World Health Organization (WHO) published its first ever list of antibiotic-resistant "priority pathogens", a catalogue of twelve families of bacteria that pose the greatest threat to human health. In this context, a new model for the study of host-pathogen interactions is becoming increasingly popular : the greater wax moth, Galleria mellonella.

The MFS efflux pump EmrKY contributes to the survival of Shigella within macrophages.

Efflux pumps are membrane protein complexes conserved in all living organisms. Beyond being involved in antibiotic extrusion in several bacteria, efflux pumps are emerging as relevant players in pathogen-host interactions. We have investigated on the possible role of the efflux pump network in Shigella flexneri, the etiological agent of bacillary dysentery.

A Soluble Metabolon Synthesizes the Isoprenoid Lipid Ubiquinone.

Ubiquinone (UQ) is a polyprenylated lipid that is conserved from bacteria to humans and is crucial to cellular respiration. How the cell orchestrates the efficient synthesis of UQ, which involves the modification of extremely hydrophobic substrates by multiple sequential enzymes, remains an unresolved issue. Here, we demonstrate that seven Ubi proteins form the Ubi complex, a stable metabolon that catalyzes the last six reactions of the UQ biosynthetic pathway in Escherichia coli.

Silver and Antibiotic, New Facts to an Old Story.

The therapeutic arsenal against bacterial infections is rapidly shrinking, as drug resistance spreads and pharmaceutical industry are struggling to produce new antibiotics. In this review we cover the efficacy of silver as an antibacterial agent. In particular we recall experimental evidences pointing to the multiple targets of silver, including DNA, proteins and small molecules, and we review the arguments for and against the hypothesis that silver acts by enhancing oxidative stress.

The UbiK protein is an accessory factor necessary for bacterial ubiquinone (UQ) biosynthesis and forms a complex with the UQ biogenesis factor UbiJ.

Ubiquinone (UQ), also referred to as coenzyme Q, is a widespread lipophilic molecule in both prokaryotes and eukaryotes in which it primarily acts as an electron carrier. Eleven proteins are known to participate in UQ biosynthesis in , and we recently demonstrated that UQ biosynthesis requires additional, nonenzymatic factors, some of which are still unknown. Here, we report on the identification of a bacterial gene, , which is required for efficient UQ biosynthesis, and which we have renamed Using several methods, we demonstrated that the UbiK protein forms a complex with the C-terminal part of UbiJ, another UQ biogenesis factor we previously identified.

The iron-sulfur cluster sensor IscR is a negative regulator of Spi1 type III secretion system in Salmonella enterica.

Iron-sulfur (Fe-S)-containing proteins contribute to various biological processes, including redox reactions or regulation of gene expression. Living organisms have evolved by developing distinct biosynthetic pathways to assemble these clusters, including iron sulfur cluster (ISC) and sulfur mobilization (SUF). Salmonella enterica serovar Typhimurium is an intracellular pathogen responsible for a wide range of infections, from gastroenteritis to severe systemic diseases.